(-5.2)(-7.8) what is it

Answer:

The smallest number of bulbs to be purchased so that the succession of bulbs produces light for at least 40 months with probability at least 0.9772 is 16.

Step-by-step explanation:

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

\(ax^{2} + bx + c, a\neq0\).

This polynomial has roots \(x_{1}, x_{2}\) such that \(ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})\), given by the following formulas:

\(x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}\)

\(x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}\)

\(\Delta = b^{2} - 4ac\)

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean \(\mu\) and standard deviation \(\sigma\), the zscore of a measure X is given by:

\(Z = \frac{X - \mu}{\sigma}\)

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

n values from a normal distribution:

The mean is \(\mu n\) and the standard deviation is \(s = \sigma\sqrt{n}\)

A company manufactures a brand of lightbulb with a lifetime in months that is normally distributed with mean 3 and variance 1.

This means that \(\mu = 3, \sigma = \sqrt{1} = 1\)

For n bulbs:

The distribution for the sum of n bulds has \(\mu = 3n, \sigma = \sqrt{n}\)

What is the smallest number of bulbs to be purchased so that the succession of bulbs produces light for at least 40 months with probability at least 0.9772?

We want that: \(S_{n} \geq 40 = 0.9772\).

This means that when X = 40, Z has a pvalue of 1 - 0.9772 = 0.0228, that is, when \(X = 40, Z = -2\). So

\(Z = \frac{X - \mu}{\sigma}\)

\(-2 = \frac{40 - 3n}{\sqrt{n}}\)

\(-2\sqrt{n} = 40 - 3n\)

\(3n - 2\sqrt{n} - 40 = 0\)

Using \(y = \sqrt{n}\)

\(3y^2 - 2y - 40 = 0\)

Which is a quadratic equation with \(a = 3, b = -2, y = -40\)

\(\Delta = b^{2} - 4ac = (-2)^2 - 4(3)(-40) = 484\)

\(y_{1} = \frac{-(-2) + \sqrt{484}}{2*3} = 4\)

\(y_{2} = \frac{-(-2) - \sqrt{484}}{2*3} = -...\)

Since y and n have both to be positive:

\(y = \sqrt{n}\)

\(\sqrt{n} = 4\)

\((\sqrt{n})^2 = 4^2\)

\(n = 16\)

The smallest number of bulbs to be purchased so that the succession of bulbs produces light for at least 40 months with probability at least 0.9772 is 16.

Answer:

The answer id D 5 units, from the options in the picture.

The options that you have given are completely different.

If the expression  (4k + 8)/4 simplifies to an expression of the form ak + b, then the value of a/b is 1/2

The expression is (4k + 8) / 4

The expression is the mathematical statement that consist of the different variables, numbers and the mathematical operator. The mathematical operators are addition, subtraction, division and multiplication.

The given expression is (4k + 8)/ 4

Solve the expression

(4k + 8) / 4 = 4k/4 + 8/4

Divide the terms

=k + 2

The result is in the form of ak + b

The value of a = 1

The value of b = 2

The value of a/b = 1/2

Therefore, the value of the expression a/b is 1/2

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An Annual is not an example of an agreement.

Answer:

34 Euros

Step-by-step explanation:

15% of 40 is 6.

40 minus 6 = 34

\([Hello,BrainlyUser]\)

Answer:

£34

Step-by-step explanation:

Given:

A pair of jeans cost £40

Discount of 15%

Question:

How much do the jeans cost after the discount

Solve:

£40 x 15% =6

£40 - 6 = 34

Hence, Jeans cost £34 after the discount

[CloudBreeze]

The ratio shows how many times one value is contained in another value.

The number of top dogs is 192.

The ratio shows how many times one value is contained in another value.

Example:

There are 3 apples and 2 oranges in a basket.

The ratio of apples to oranges is 3:2 or 3/2.

We have,

The ratio of top dogs to fat cats was 24 to 19.

if they were 152 fat cats.

This means,

Number of top dogs = 24x

Number of fat cats = 19x

Now,

Number of fat cats = 152

This means,

152 = 19x

x = 8

Now,

Number of top dogs = 24x

= 24x

= 24 x 8

= 192

Thus,

The number of top dogs is 192.

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Answer:

y=7-1/2x

Step-by-step explanation:

if you try this rule with all of the numbers, it will come out as true

Answer: 2x5x1, 1x10x1 (in any order) and any 3 multiples that make 10

Step-by-step explanation:

Answer:

There are multiple possible sets of dimensions for a rectangular prism with a volume of 10 cubic feet. Here are some possible solutions:

A rectangular prism with dimensions of 1 ft x 2 ft x 5 ft (length x width x height) would have a volume of 10 cubic feet, since 1 x 2 x 5 = 10.

A rectangular prism with dimensions of 2 ft x 1 ft x 5 ft (length x width x height) would also have a volume of 10 cubic feet, since 2 x 1 x 5 = 10.

A rectangular prism with dimensions of 0.5 ft x 1 ft x 20 ft (length x width x height) would also have a volume of 10 cubic feet, since 0.5 x 1 x 20 = 10.

A rectangular prism with dimensions of 5 ft x 1 ft x 2 ft (length x width x height) would have a volume of 10 cubic feet, since 5 x 1 x 2 = 10.

There are infinitely many other possible sets of dimensions for a rectangular prism with a volume of 10 cubic feet.

As per the angle sum property, the interior angles that form the triangle is option

B. 60, 60, 60°

C. 40.50,90°

D. 30.60.90*

Angle sum property

Angle sum property states that the sum of all the interior angles of the triangle is equal to 180 degrees.

Given,

Here we have the list of interior angles

A. 45, 45, 45*

B. 60, 60, 60°

C. 40.50,90°

D. 30.60.90*

E. 90,90°, 45°

F. 90, 90, 90°

Now, we have to find in which for these angle will form the tringle.

As per the definition of the angle sum property, the sum of all the interior angle of the triangle is 180°.

Based on these we have to verify each of the given interior angles,

A) 45 + 45 + 45 = 135

B. 60 + 60 + 60 = 180

C. 40 + 50 + 90 = 180

D. 30 + 60 + 90 = 180

E. 90 + 90 + 45 = 225

F. 90 + 90 + 90 = 270

Therefore, based on these values we have identified that the options (B), (C), and (D) forms the triangle.

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Answer:

it's 0.5

Step-by-step explanation:

The best estimate of the correlation coefficient for the data set is 0.5.

So, option c is the correct answer.

The correlation coefficient is a measure of how similar two datasets are acting.

The range of correlation coefficient is [-1, 1]

When the correlation coefficient comes out as -1, it means that both the datasets are negatively oppositely correlated. One data increases, and other data starts to decrease in the opposite direction.

When the correlation coefficient comes out below 0, values are negatively correlated.

If the correlation coefficient comes out as 0, that means both the data sets are uncorrelated with respect to how we compare them.

When the correlation coefficient comes out > 0, that means both datasets' values are positively correlated.

If the correlation coefficient comes out as 1, then the values grow exactly similarly, in the same direction.

The best estimate of the correlation coefficient for the data set is 0.5.

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The graphing form of the function g(x) is: C) none of the answer choices.

The function g(x) = \(x^2 + 4x - 7\)is already in the standard form of a quadratic equation. In graphing form, a quadratic equation can be represented as y =\(ax^2 + bx + c,\) where a, b, and c are constants.

Comparing the given function g(x) =\(x^2 + 4x - 7\)with the standard form, we can identify the coefficients:

a = 1 (coefficient of x^2)

b = 4 (coefficient of x)

c = -7 (constant term)

Therefore, the graphing form of the function g(x) is:

C) none of the answer choices

None of the given answer choices (A, B, D, or E) accurately represents the graphing form of the function g(x) =\(x^2 + 4x - 7\). The function is already in the correct form, and there is no equivalent transformation provided in the answer choices. The given options either represent different equations or incorrect transformations of the original function.

In graphing form, the equation y = \(x^2 + 4x - 7\) represents a parabolic curve. The coefficient a determines the concavity of the curve, where a positive value (in this case, 1) indicates an upward-opening parabola.

The coefficients b and c affect the position of the vertex and the intercepts of the curve. To graph the function, one can plot points or use techniques such as completing the square or the quadratic formula to find the vertex and intercepts. Option C

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9514 1404 393

Answer:

  12.5 square inches

Step-by-step explanation:

The area of the base can be written as ...

  B = LW

Then the volume formula ...

  V = LWH

can be written in terms of the base area as ...

  V = BH

The base area can be found by dividing by the height:

  B = V/H = (50 in³)/(4 in) = 12.5 in²

The area of the base is 12.5 square inches.

Letters are

No repetitions

Distinct permutation:-

By finding all the four slopes, we can see that the word is ECHA.

We know that the general linear equation can be written as:

y = a*x + b

Where a is the slope and b is the y-intercept.

We know that if the line passes through (x₁, y₁) and (x₂, y₂) then the slope is:

s = (y₂ - y₁)/(x₂ - x₁)

With that formula we can get the slopes.

1) Using the points (0, 3) and (2, 4).

m = (4 - 3)/(2 - 0) = 1/2, so the letter is E.

2)Using (-1, -12) and (1, -8)

m = (-8 + 12)/(1 + 1) = 4/2 = 2, so the letter is C.

3) We have (2, -6) and (-4, -3) so:

m = (-3 + 6)/(-4 - 2) = 3/-6 = -1/2, so the letter is H

4)we can use the points (0, 3) and (1, 1), so:

m = (1 - 3)/(1 - 0) = -2, so the letter is A

Then the word is ECHA

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Answer: 25

Step-by-step explanation:

7 + -6(-3)

7 + 18 = 25

Answer:

25

Step-by-step explanation:

x= -6

7+ -6(-3)=

7+ (18)=25

25

Answer:

i think it is..

Step-by-step explanation:

Answer:

First one would be y=2x (the cost of each ticket is 2 and x is the number of tickets that you are buying)

The second one is y=x+10 (each ticket is one and 10 is the one time set up fee)

Answer:

7.36 g/cm3

Step-by-step explanation:

Density = mass ÷ volume

Mass in grams = 9200g

Volume in cm3 = 1250cm3

9200 ÷ 7850 = 7.36

7.36 is already in 2 d.p.

The daily average temperature in Darrtown in 2013 is B. 64°F

Temperature is a measure of how hot or cold something is expressed in terms of one of several scales, including Fahrenheit and Celsius. The direction in which heat energy will spontaneously flow is indicated by temperature.

Given that in 2011, the average daily temperature in Darrtown was 65°F, and in 2012, the average daily temperature increased by 3%. The temperature in 2012 will be:

= 65 + (3% × 65)

= 66.95°F

Then, it decreased by 4.5% in 2013. This will be:

= 66.95 - (4.5% × 66.95)

= 64°F

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Answer:20%

Step-by-step explanation

When you multiply 64x100, you'd get 6400. Then you divide that by 80, you get 80. And when you have 80/100, you have 20 left out of the 100. So it is 20%.

Answer:

The Yankees lost 20% of their games.

Step-by-step explanation:

We need to find the percentage of what games the Yankees lost.

=========================================

We need to figure out what percentage of 64 is part of 80 (the winning percentage) first.

We would have to divide 64 by 80 and the multiply the quotient by 100.

\(\frac{64}{80} = 0.8 * 100 = 80\%\)

The Yankees won 80% of the games.

=========================================

To find the losing percentage we have to subtract 80% from the 100% of the games.

100% - 80% = 20%

The Yankees lost 20% of the games.

=========================================

Hope this helps!

Step-by-step explanation:

median:3

25th Percentile: 2.5

50th Percentile: 3

75th Percentile: 4

Interquartile Range: 1.5

In a case whereby Juan buys candy that costs $8 per pound and will spend at least $48 on candy  the possible numbers of pounds he will buy written in inequality is is p>5 (at least 5 pounds).

Inequality in math refers to a statement that one quantity is either greater than, less than, or not equal to another quantity. Inequalities are often represented using symbols such as "<" (less than), ">" (greater than), or "≤" (less than or equal to) and "≥" (greater than or equal to). For example, the inequality "x > 3" states that the variable "x" is greater than the value of 3. The inequality "y ≤ 5" means that the variable "y" is less than or equal to 5.

From the question, p = number of pounds Juan will buy.

candy=costs $8 per pound

$20/$4 = 5 pounds

p>5

at least 5 pounds

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Answer:

m = 5

Explanation:

The given expression is

First, we need to apply the distributive property, so

Then, subtract 30 from both sides

Add 7m to both sides

Finally, divide both sides by 8

Therefore, the answer is m = 5

During the exponential phase, e.coli bacteria in a culture increase in number at a rate proportional to the current population. If growth rate is 1.9% per minute and the current population is 172.0 million, the population 7.2 minutes from now can be calculated using the following formula:

P(t) = P ₀e^(rt)where ,P₀ = initial population r = growth rate (as a decimal) andt = time (in minutes)Substituting the given values, P₀ = 172.0 million r = 1.9% per minute = 0.019 per minute (as a decimal)t = 7.2 minutes

The population after 7.2 minutes will be:P(7.2) = 172.0 million * e^(0.019*7.2)≈ 234.0 million (rounded to the nearest tenth)Therefore, the population of e.coli bacteria 7.2 minutes from now will be approximately 234.0 million.

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Answer:

the correct answer is c. 415in

Step-by-step explanation:

You have to multiply the base radius by the height.

Approximately 138.3 grams of the compound will remain after 8 hours. The decay of a radioactive compound is an exponential process, which can be modeled by the equation:

N(t) = N₀ * e^(-λt)

where N(t) is the amount of the compound remaining at time t, N₀ is the initial amount of the compound, λ is the decay constant, and e is the mathematical constant known as Euler's number.

To find the amount of the compound remaining after 8 hours, we need to plug in the given values into the equation above. We know that the initial mass of the compound is 260 grams, and the decay rate is 3.8% per hour, which means that the decay constant λ is equal to 0.038. Therefore, the equation becomes:

N(8) = 260 * e^(-0.038 * 8)

Simplifying this equation gives:

N(8) = 260 * e^(-0.304)

N(8) ≈ 138.3 grams

Therefore, approximately 138.3 grams of the compound will remain after 8 hours.

It's important to note that this calculation assumes that the decay rate remains constant over time, which may not always be the case in reality. Additionally, the actual amount of the compound remaining may vary due to experimental error or other factors.

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Answer:

$280

Step-by-step explanation:

7•40=$280

Answer:

Silas

Step-by-step explanation:

300 / 2 = 150

150 / 60 = 2.5

So, Marshall hands out 2.5 brochures per minute.

240 / 90 = 2.6

And, Silas hands out 2.6 brochures per minute.

2.5 < 2.6

Answer:

silas is the answer

Step-by-step explanation:

I got it right :)