The manager of a grocery store has selected a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3.0 minutes. It is known that the standard deviation of the checkout time is 1 minute. Refer to Exhibit 8-2. If the confidence coefficient is reduced to .80, the standard error of the mean _____.
Answers
Answer:
The standard error of the mean remains unchanged.
Step-by-step explanation:
Given that:
The standard error (S.E) of the mean \(= \dfrac{\sigma}{\sqrt{n}}\) with is independent of confidence coefficient.
The margin of error \(E = z \times S.E\)
This explains the claim that as the confidence coefficient reduces, the z-value also reduces, so as the Margin of error (E) but the standard error will always remain unchanged.
i.e.
From the question;
sample size n = 100
standard deviation = 1
mean = 3.0
The standard error (S.E) of the mean \(= \dfrac{1}{\sqrt{100}}\)
= 0.1
So, if the confidence coefficient is reduced to 0.80, the standard error of the mean remains unchanged.
Related Questions
Find the slope of the line.
Answers
Answer:
1/5
Step-by-step explanation:
Answer:
m= -1/4
Step-by-step explanation:
Points on the line: ( -4, -1) and (0, -2)
Slope:
m=(y2-y1)/(x2-x1)
m=(-2+1)/(0+4)
m=(-1)/4
m= -1/4
Please help me out, the question is in the image attached.
Answers
9514 1404 393
Answer:
d = 2.5 ft
Step-by-step explanation:
Similar figures have proportional linear measures.
diameter/height = d/1 = 10/4
d = 5/2 = 2.5 . . . . feet
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The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day. They would like the estimate to have a maximum error of 0.11
gallons. A previous study found that for an average family the standard deviation is 2.3
gallons and the mean is 19.9
gallons per day. If they are using a 80%
level of confidence, how large of a sample is required to estimate the mean usage of water? Round your answer up to the next integer.
Answers
Answer:
The formula to calculate the sample size needed to estimate a population mean with a specified margin of error is:
n = (Z*σ/E)^2
Where:
Z = the Z-score for the desired level of confidence
σ = the standard deviation of the population
E = the maximum error (margin of error) allowed
n = the sample size
Substituting the given values:
Z = 1.28 (for an 80% level of confidence)
σ = 2.3 gallons (from the previous study)
E = 0.11 gallons (the maximum error allowed)
n = (1.28*2.3/0.11)^2
n = 89.13
Rounding up to the next integer, the sample size required is 90. Therefore, the water works commission needs a sample of 90 households to estimate the mean household usage of water in the small town with a maximum error of 0.11 gallons and an 80% level of confidence.
Step-by-step explanation:
The ________ distribution is used by PERT analysis to calculate expected activity times and variances.A. GaussianB. AlphaC. BetaD. NormalE. Binomial
Answers
Answer: The distribution used by PERT (Program Evaluation and Review Technique) analysis to calculate expected activity times and variances is the Beta distribution. Therefore, the correct answer is C. Beta.
Step-by-step explanation:
Why was the Battle of Fallen Timbers important for the new democracy?
Please write 3 paragraphs, stating 3 different reasons why the battle was important. (Paragraphs should be 4-6 sentences each
Answers
The Whiskey Rebellion put an end as a consequence of the Battle of Fallen Timbers; that had a significant outcome.
Why was Battle of Fallen Timbers important to the US?After the Battle of Fallen Timbers, the Indians agreed to the Treaty of Greenville, which gave the United States authority over most of the river crossings in the Old Northwest Territory as well as vital sites like Detroit.
The Battle of Fallen Timbers is considered to be the last battle of the American Revolution and which also helped the new country start expanding the territory to the west.
This will effectively ensured American dominance over the Indian tribes. The Whiskey Rebellion; which was the first significant confrontation between the nascent American government and it's inhabitants, which was put a stop to by it, and peace was restored.
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fill in the bank. In the triangle below, x = . Round your answer 2 decimal places
Answers
The calculated value of x in the triangle is 23.57 degrees
How to calculate the value of xFrom the question, we have the following parameters that can be used in our computation:
The right triangle
From the triangle, we have
Angle x
Also, we have the following sides in relation to x
Opposite = 6
Hypotenuse = 15
This means that we make use of the sine ratio
i.e. sin = opposite/hypotenuse
So, we have
sin(x) = 6/15
Evaluate
sin(x) = 0.4
Take the arc sin of both sides
x = 23.57
Hence, the value of x is 23.57 degrees
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Automobile manufacturers are interested in the difference in reaction times for drivers reacting to traditional incandescent lights and to LED lights. A sample of 12 drivers are told to press a button as soon as they see a light flash in front of them and the reaction time was measured in milliseconds. Each driver was shown each type of light. A 99% confidence interval for the average difference between the two reaction times (traditional - LED) was (-30.83, 271.17). Which of the following is the appropriate conclusion?
Question 5 options:
1)
We are 99% confident that the average difference in reaction times for all drivers is negative, with the higher reaction time being with LED lighting.
2)
We are 99% confident that the average difference in reaction times for all drivers is negative, with the higher reaction time being with traditional lighting.
3)
We are 99% confident that the average difference in reaction times for all drivers is positive, with the higher reaction time being with LED lighting.
4)
We are 99% confident that the average difference in reaction times for all drivers is positive, with the higher reaction time being with traditional lighting.
5)
There is not a significant difference in the average reaction times for the two different types of lighting.
Answers
Though the difference is not numerically significant, it is important to unitary method keep in mind that there might still be a real difference that this group does not account for.
What is unitary method ?The unit method is a strategy for handling issues that entails first figuring out the value of a single unit, then multiplying that value to figure out the needed value. Simply stated, the unit method is used to extract a unique unit number from a multiple that is given. For example, 40 pens would cost 400 rupees, which is equal to the expense of one pen. This procedure might follow a conventional procedure. a distinct nation. anything with a distinct character. Its adjoint and inverse are identical in terms of mathematics, algebra, linear algebra, mathematical analysis, or mathematics of matrices or operators.
The disparity in reaction latencies between conventional incandescent lights and LED lights has a 99% confidence range of (-30.83, 271.17) milliseconds. We cannot definitively determine whether the average difference is positive or negative because the interval includes both positive and negative numbers.
The best conclusion is option 5, which states that there isn't much of a difference between the two kinds of lighting's typical response rates. Though the difference is not numerically significant, it is important to keep in mind that there might still be a real difference that this group does not account for.
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in a study, the sample is chosen by using the random number generator on your ti-83 to generate a number, like 3, then taking every 3rd person in the list
Answers
Systematic sampling involves selecting every nth item from a list, potentially with bias and non-random results, so choose carefully.
The method used to choose the sample in this study is called "systematic sampling". This involves selecting a starting point (in this case using a random number generator) and then selecting every nth item (in this case, every 3rd person) from a list to form the sample. This type of sampling can introduce biases in the sample if the list has some pattern or structure, so it's important to be aware of these potential issues when using this method.
In systematic sampling, the selection of each member of the sample is based on a fixed and systematic rule. The advantage of this method is that it is easy to implement and cost-effective. The disadvantage is that if the list has any pattern or structure, such as alternation or clustering, the sample may not be representative of the population. It's important to carefully consider the list and choose an appropriate starting point and interval to reduce the potential for bias.
It's also worth noting that systematic sampling may not result in a random sample, as the sample members may not be independent of each other. This can have implications for the validity of inferences made from the sample to the population. Therefore, it's important to carefully consider the properties of the population and the goals of the study when choosing a sampling method.
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If 5/11 of the class are girls, what is the ratio of girls to boys?
Answers
Answer:
5:6
Step-by-step explanation:
The entire class is 11/11.
Girls: 5/11 of the class.
Boys: 11/11 - 5/11 = 6/11
Ratio of girls to boys:
5/11 / 6/11 = 5/11 × 11/6 = 5/6
Answer: 5:6
Derive the positive square root of 982081
Answers
Answer: 991
square root of 982081 hope this helps
Can someone pls explain
Answers
163. The distance between A(-5, 6) and B(5, -5) is: AB ≈ 14.9 units
164. Applying the Pythagorean theorem, we have: Diagonal ≈ 21.2 ft.
165. Marissa's final answer is wrong. It should be, c = √676 = 26 units.
166. Missing side = 29 ft.
What is the Pythagorean Theorem?The Pythagorean theorem states that c² = a² + b², given that a and b are shorter legs and c is the hypotenuse or longest leg of the right triangle.
163. The distance between A(-5, 6) and B(5, -5):
AB = √[(5−(−5))² + (−5−6)²]
AB = √221
AB ≈ 14.9 units
164. Apply the Pythagorean theorem to find the diagonal:
Diagonal = √(15² + 15²) ≈ 21.2 ft.
165. The answer Marissa got is wrong. The final answer which is the square root of 676 is:
c = √676 = 26 units.
166. Missing side = √(20² + 21²) = 29 ft.
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A recent survey showed that exactly 38%
of people in a town buy the local
newspaper. There are 2450 people in the
town.
a) How many people in the town buy the
local newspaper?
b) How many people in the town do not
buy the local newspaper?
Answers
Answer:
a) .38 × 2,450 = 931 people buy the local newspaper.
b) 2,450 - 931 = 1,519 people do not buy the local newspaper.
There are 15 boys and 5 girls in a class.
The mean amount of time of finishing a test was 45 minutes for the boys and 55
minutes for the girls.
What was the mean of the class?
Give your answer in minutes to one decimal place.
Answers
Answer: 50.0
Step-by-step explanation:
1. Add 45+55=100
2. Divide 100 by 2 =50
3. Add a decimal after 50.0
Find the value of y for the given value of x.
y=2−9x;x=2/3
Answers
Answer:
-4
Step-by-step explanation:
y=2-9×(2/3)=2-6= -4
I don’t understand this question.
Answers
Explanation: x=7 in this case. When its says, TQS, it means that particular angle.
There were 4 golden retrievers at the dog park last Saturday, along with 4 other dogs.
Considering this data, how many of the next 18 dogs to arrive at the park next Saturday
should you expect to be golden retrievers?
Answers
Answer:
9 Golden Retrievers.
Step-by-step explanation:
If there were 8 dogs last Saturday, and half were golden retrievers, next Saturday should have half golden retrievers. 18 divided by 2 equals 9.
\(18 \div 2 = 9\)
Hope this helped :)
Answer:
ryt
Step-by-step explanation:
help ight now 88 POINTS!
Answers
Divide. Write your answer in simplest form. 9/2 / 1/4
Answers
Answer:
18
Step-by-step explanation:
9/2 / 1/4
keep 9/2
Change the operation to multiplication
flip 1/4 into 4 or 4/1
multiply on top and bottom and get 36/2
which 36/2 is 18 and 18 is the answer
Brainliest?
A taxi charges 2.50 plus .50 fee for each mile. If the ride costs 7.50 how many miles did he travel
Answers
Answer: 10 miles
Step-by-step explanation:
Mile 1: 3.00
Mile 2: 3.50
Mile 3: 4.00
Mile 4: 4.50
Mile 5: 5.00
Mile 6: 5.50
Mile 7: 6.00
Mile 8: 6.50
Mile 9: 7.00
Mile 10: 7.50
Use the graph below to find the slope of the line that goes through the points
|(1, 2) and (6,6).
Answers
Answer:
4/5
Step-by-step explanation:
m=y2-y1/x2-x1
=6-2/6-1
4/5
NEED HELP AS SOON AS POSSIBLE which interval describes where the graph of the function is negative
Answers
Answer:
2 < x < ∞
Step-by-step explanation:
We want where the value of y is less than zero
The value of the graph is less than zero is from x=2 and continues until x = infinity
2 < x < ∞
Answer:
\(\boxed{2 < x < \infty}\)
Step-by-step explanation:
The value of y should be less than 0 for the graph of the function to be negative.
In the graph, when it startes from x is 2 the value becomes less than 0 and it keeps continuing until x is equal to infinity.
\(2 < x < \infty\)
What is the y-intercept of the graph
of 3x - 4y = 12
Pls help
Answers
Answer:
Hey there!
3x-4y=12
-4y=-3x+12
y=3/4x-3
So the y-intercept is -3.
Let me know if this helps :)
Answer:
The y-intercept is at (0, -3).
Step-by-step explanation:
Where the graph intercepts the y axis x = 0 so we have the equation:
3(0) - 4y = 12
-4y = 12
y = 12/ -4
y = -3.
Bob mows lawns for 5 weeks during summer break. He mows 2 lawns every day. By the end of 5 weeks, how many lawns has Bob mowed?
Answers
Answer: 70
Step-by-step explanation:
7 days a week x 2 lawns = 14
14 lawns x 5 weeks = 70 lawns
Answer:
70 lawns
Step-by-step explanation:
If Bob mows lawns every day for 5 weeks this is how the equation would work:
2 * 7 = 14
14 * 5 = 70
I got the 7 because there's seven days per week.
why is the sky blue? why is the water blue?
Answers
The sky appears blue because of Rayleigh scattering while water appears blue due to selective absorption and scattering of light.
Why does the sky appear blue and the water blue?The blue color of the sky is a result of Rayleigh scattering which occurs when the Earth's atmosphere scatters shorter wavelengths of light (blue and violet) more efficiently than longer wavelengths (red and orange).
When sunlight enters the atmosphere, the blue light is scattered in all directions by the molecules and tiny particles present in the air creating the blue appearance of the sky.
Similarly, water appear blue due to selective absorption and scattering of light. Water molecules selectively absorb colors from the visible light spectrum and absorb longer wavelengths (such as red) more effectively than shorter wavelengths (such as blue).
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Brandon opened a credit card at a department store with an APR of 14.99% compounded monthly. What is the APY on this credit card? A. 1.25% B. 29.98% C. 16.06% D. 19.55%
Answers
Answer:
real annual rate= 0.1606 = 16.06%
Step-by-step explanation:
Giving the following information:
APR= 14.99% = 0.1499
First, we will determine the nominal monthly rate:
Nominal monthly rate= 0.1499/12
Nominal monthly rate= 0.01249
Now, to calculate the real annual rate, we need to use the following formula:
real annual rate= [(1 + Nominal monthly rate)^n] - 1
real annual rate= [(1.01249^12) - 1]
real annual rate= 0.1606 = 16.06%
Find the smallest whole number by which 16087 should be multiplied or divided to get a perfect square
Answers
There is no whole number by which you can multiply or divide 16087 to make it a perfect square.
To determine by which number you should multiply or divide 16087 to make it a perfect square, we can analyze its prime factorization. The prime factorization of 16087 is 13 × 1237.
In order to make 16087 a perfect square, we need each prime factor to have an even exponent. However, when we examine the prime factors of 16087, we find that both 13 and 1237 have an exponent of 1.
To make the exponents even, we need to multiply or divide 16087 by additional prime factors and their respective exponents. However, since 16087 is a product of two prime numbers (13 and 1237), we cannot introduce any additional prime factors to make the exponents even.
A perfect square is a number that can be expressed as the product of two equal factors. In the case of 16087, it cannot be transformed into a perfect square by multiplying or dividing by any whole number. The prime factors 13 and 1237 remain with an exponent of 1 each, indicating that there is no integer that can be applied to make them equal and convert 16087 into a perfect square.
Therefore, there is no whole number by which you can multiply or divide 16087 to make it a perfect square.
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The annual rate, r, it takes for 1 dollar to grow to X dollars in 2 years is given by the formula X = (1+r) ².
Find the rate necessary for a dollar to triple in 2 years.
Answers
The rate of interest is 73%.
What is the annual rate?
The term annual percentage rate of charge refers to the interest rate for an entire year rather than just a monthly fee or rate as applied on a loan, mortgage loan, credit card, etc. It can also be referred to as a nominal APR or an effective APR. It is an annual rate of a finance charge.
Given that 1 dollar to grow to X dollars in 2 years is given by the formula X = (1+r) ².
A dollar to triple in 2 years.
Thus putting X = 3 in X = (1+r) ²
3 = (1+r) ²
Take square root on both sides:
√3 = 1 + r
Subtract 1 from both sides:
r = √3 - 1
r = 0.73
r = 73%
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I need help pls ANYTHING WILL help ASAP
Answers
solution: x=7
first step: removing the parantheses — distribute 2 which would make it 3x+8+12x=113
second step: collect like terms — 3x + 12x = 15x which would make the equation 15x+8=113
third step: move the constant to the right — 15x=113-8
fourth step: calculate — 15x=105
fifth step: divide both sides which would make the answer x=7
Hoped this helped !!
7x-8y=13 can someone please help me
Answers
Answer:
A
Step-by-step explanation:
Sub in the point given, (3, 1), and check if the equation holds true
7(3) - 8(1) = 13
21 - 8 = 13
13 = 13
The equation held true, therefore, the point (3, 1) is a solution
The number of widgets that a manufacturing plant can produce varies jointly as the number o
workers and the time that they have worked.
1) Find the constant of proportionality, k, to 2 decimal places if 640 workers work 11 hours and
produce 3993.6 widgets.
k
2) How many widgets (to the nearest tenth) can be produced by 650 workers in 27 hours?
Widgets =
Add Work
Calculator
Answers
Answer:
Step-by-step explanation:
I think that the answer is ................................................................................................................................................Your adopted