The life of light bulbs is distributed normally. The standard deviation of the lifetime is 15 hours and the mean lifetime of a bulb is 520 hours. Find the probability of a bulb lasting for at most 528 hours. Round your answer to four decimal places.

Answers

Answer 1

Answer:

0.7031 = 70.31% probability of a bulb lasting for at most 528 hours.

Step-by-step explanation:

Normal Probability Distribution

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

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

The standard deviation of the lifetime is 15 hours and the mean lifetime of a bulb is 520 hours.

This means that [tex]\sigma = 15, \mu = 520[/tex]

Find the probability of a bulb lasting for at most 528 hours.

This is the p-value of Z when X = 528. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{528 - 520}{15}[/tex]

[tex]Z = 0.533[/tex]

[tex]Z = 0.533[/tex] has a p-value of 0.7031

0.7031 = 70.31% probability of a bulb lasting for at most 528 hours.


Related Questions

Please help ASAP !!! Thank you !

Answers

(1) =(a+b)(3c-d) =a(3c-d)+b(3c-d) =3ac-ad+3bc-bd

(2) =(a-b)(c+2d) =a(c+2d)-b(c+2d) =ac+2ad-bc-2bd

(3) =(a-b)(c-2d) =a(c-2d)-b(c-2d) =ac-2ad-bc+2bd

(4) =(2a+b)(c-3d) =2a(c-3d)+b(c-3d) =2ac-6ad+bc-3bd

(x+a)(x-a) = x² -25 then what is the value of a ?​

Answers

Answer:

The value of A is 5

......

[tex]\huge{\boxed{\boxed { ⎆ Answer :- }}} \ [/tex]

[tex](x + a)(x - a) = {x}^{2} - 25[/tex]

Use, the algebraic identity ↦

[tex](a + b)(a - b) = {a}^{2} - {b}^{2} [/tex]

So,

[tex](x + a)(x - a) = {x}^{2} - 25 \\ \\ ⟹ \sqrt{25} = 5[/tex]

↦So, the value of a is 5.

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐

A hotel manager believes that 23% of the hotel rooms are booked. If the manager is right, what is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%

Answers

Answer:

0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

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

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

A hotel manager believes that 23% of the hotel rooms are booked.

This means that [tex]p = 0.23[/tex]

Sample of 610 rooms

This means that [tex]n = 610[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.23[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.23*0.77}{610}} = 0.017[/tex]

What is the probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%?

p-value of Z when X = 0.23 + 0.03 = 0.26 subtracted by the p-value of Z when X = 0.23 - 0.03 = 0.2. So

X = 0.26

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.26 - 0.23}{0.017}[/tex]

[tex]Z = 1.76[/tex]

[tex]Z = 1.76[/tex] has a p-value of 0.9608

X = 0.2

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.2 - 0.23}{0.017}[/tex]

[tex]Z = -1.76[/tex]

[tex]Z = -1.76[/tex] has a p-value of 0.0392

0.9608 - 0.0392 = 0.9216

0.9216 = 92.16% probability that the proportion of rooms booked in a sample of 610 rooms would differ from the population proportion by less than 3%

Will marl brainliest! Please help :,)

Answers

Answer:

x= -4

Step-by-step explanation:

A line is 180 degrees. This means that we can use the equation

60+x+124=180

Simplify:

184+x=180

x= -4

We can check this answer by plugging it back in:

60 + (-4) +124 =180

180=180

I hope this helps!

Step-by-step explanation:

[tex]60 + 124 + x = 180 \\ 180 - 184 = x \\ x = - 4[/tex]

What is the volume of a cone with a height of 27 cm
and a radius of 13 cm? Round your answer to the
nearest tenth.
Use the button on your calculator to complete this
problem.
V=
cm3

Answers

Answer:4778.3 cm^3

Step-by-step explanation: The formula for volume of a cone is V=1/3h pi r^2. By plugging in the height and the radius we get our answer.

Answer:

4778.4 :)

Step-by-step explanation:

You are on a 5.6-mile run and have already run 1.98 miles. How many more miles do you need to run?

Answers

Answer:

3.62 miles need to be run

5.6-1.98=3.62 miles left to run

16.7.1
One-fifth of the length of a foot-race is 7 miles. Find the length of the race.

Answers

Answer:

35 miles

Step-by-step explanation:

1/5 = 7

so each part is 7, which means that 5 parts would be 7*5.

7*5 = 35

cross check:

35/5 = 7

hope this helps :)

The answer is 35/7 =7

Suppose that you are headed toward a plateau 37 meters high. If the angle of elevation to the top of the plateau is ​, how far are you from the base of the​ plateau?

Answers

Answer:

21.36 meters

Step-by-step explanation:

Given

[tex]h = 37m[/tex]

[tex]\theta = 60^o[/tex]

Required

The distance from the base (b)

The question illustrates right-angled triangle (see attachment)

To solve for (b), we make use of tangent formula

[tex]\tan(60)=\frac{h}{b}[/tex]

Make b the subject

[tex]b =\frac{h}{\tan(60)}[/tex]

So:

[tex]b =\frac{37}{\tan(60)}[/tex]

[tex]b =\frac{37}{1.7321}[/tex]

[tex]b =21.36[/tex]

I thought x-7 was the right answer because don't you need to subtract? But apparently it was wrong so then which one is the correct answer?​

Answers

Answer:

It is 7x-7

Step-by-step explanation:

You have to add the two expressions, not subtract them.

Answer:

no you need to add, it would be 7x - 7

Step-by-step explanation:

You need to look at the line...they gave you the measurement for PR, and the measurement for RS...and they want you to find PS

You need to add because both PR and RS come together to form PS

Symposium is part of a larger work referred to as Plato's Dialogues. Wishart and Leach† found that about 21.4% of five-syllable sequences in Symposium are of the type in which four are short and one is long. Suppose an antiquities store in Athens has a very old manuscript that the owner claims is part of Plato's Dialogues. A random sample of 498 five-syllable sequences from this manuscript showed that 129 were of the type four short and one long. Do the data indicate that the population proportion of this type of five-syllable sequence is higher than that found in Plato's Symposium? Use ???? = 0.01.

Answers

Complete Question

ymposium is part of a larger work referred to as Plato's Dialogues. Wishart and Leach† found that about 21.4% of five-syllable sequences in Symposium are of the type in which four are short and one is long. Suppose an antiquities store in Athens has a very old manuscript that the owner claims is part of Plato's Dialogues. A random sample of 498 five-syllable sequences from this manuscript showed that 129 were of the type four short and one long. Do the data indicate that the population proportion of this type of five-syllable sequence is higher than that found in Plato's Symposium? Use = 0.01.  

a. What is the value of the sample test statistic? (Round your answer to two decimal places.)  

b. Find the P-value of the test statistic. (Round your answer to four decimal places.)

Answer:

a) [tex]Z=2.45[/tex]

b) [tex]P Value=0.0073[/tex]

Step-by-step explanation:

From the question we are told that:

Probability of Wishart and Leach [tex]P=21.4=>0.214[/tex]

Population Size [tex]N=498[/tex]

Sample size [tex]n=12[/tex]

Therefore

[tex]P'=\frac{129}{498}[/tex]

[tex]P'=0.2590[/tex]

Generally the Null and Alternative Hypothesis is mathematically given by

[tex]H_0:P=0.214[/tex]

[tex]H_a:=P>0.214[/tex]

Test Statistics

[tex]Z=\frac{P'-P}{\sqrt{\frac{P(1-P)}{n}}}[/tex]

[tex]Z=\frac{0.2590-0.214}{\sqrt{\frac{0.214(1-0.214)}{498}}}[/tex]

[tex]Z=2.45[/tex]

Therefore P Value is given as

[tex]P Value =P(Z\geq 2.45)[/tex]

[tex]P Value =1-P(Z\leq 2.45)[/tex]

[tex]P Value =1-0.99268525[/tex]

[tex]P Value=0.0073[/tex]

Using the quadratic formula, which of the following are the zeros of the quadratic equation below? y=x^2-x-5

Answers

Answer:

The roots(Zeros) are

x=2.7913 and -1.7913

Please help! Thank you!​

Answers

Answer:

B

Step-by-step explanation:

Divide both sides by 3

Take square root of both sides.

Add 9 to both sides.

The sum of three numbers is 3. The first number minus the second plus the third is -3. The first minus the third is 1 more than the second.
Find the numbers. What is the first number? What is the second number? What is the third number?​

Answers

Answer: The first number is 2, the second number is 3 and the third number is -2

Step-by-step explanation:

Let the first number be 'x', the second number be 'y' and the third number be 'z'

The equations according to the question becomes:

⇒ x + y + z = 3              ....(1)

⇒ x - y + z = -3              ....(2)

⇒ x - z = 1 + y              ....(3)

Rearranging equation 3:

⇒ x - y = 1 + z                .....(4)

Putting in equation 2:

⇒ 1 + z + z = -3

⇒ 1 + 2z = -3

⇒ z = -2

Putting this value in equation 4 and equation 1, we get:

⇒ x - y = -1

⇒ x + y = 5

Cancelling 'y' by eliminiation method and equation becomes:

⇒ 2x = 4

⇒ x = 2

Putting value of 'x' and 'z' in equation 1:

⇒ 2 + y - 2 = 3

⇒ y = 3

Hence, the first number is 2, the second number is 3 and the third number is -2

Write an equation that represents the line.
Use exact numbers

Answers

y=2/3x+2/3 bc slope is 2/3 and 4-2/4-1=2/3

The ocean surface is at 0 ft elevation. A diver is underwater at a depth of 138 ft. In this area, the ocean floor has a depth of 247 ft. A rock formation rises to a peak 171 ft above the ocean floor. How many feet below the top of the rock formation is the diver?

Answers

Answer:

The ocean surface is at 0 ft elevation. A diver is underwater at a depth of 138 ft. In this area, the ocean floor has a depth of 247 ft.

Step-by-step explanation:

The sum of 3 consecutive odd numbers is 183. What is the third number in this sequence?

Answers

Answer:

61

Step-by-step explanation:

3x + 6 = 183

3x = 177

x = 59

(x+2) = (59+2) = 61

It is correct on khan academy

Answer:

The third number in this sequence is 63.

Step-by-step explanation:

Let the first odd number be x.

Since our sequence are consecutive odd numbers, the second term must be (x + 2) and the third (x + 4). If we only add one, we will get even numbers.

Their sum is 183. Hence:

[tex]x+(x+2)+(x+4)=183[/tex]

Solve for x. Combine like terms:

[tex]3x+6=183[/tex]

Subtract six from both sides:

[tex]3x=177[/tex]

And divide both sides by three. Hence:

[tex]x=59[/tex]

Therefore, our sequence is 59, 61, and 63.

The third number in this sequence is 63.

Note: If we do not get an odd number or if we get a fraction for x, we can conclude that no three consecutive integers sum to 183.

someone please help. you have to find ge and I have no idea how to​

Answers

Hello,

3x+9+8x-25=28

11x-16=28

x=44/11

x=4

So, GE=3x+9=3*11+9=42

A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. If the dean wanted to estimate the proportion of all students receiving financial aid to within 1% with 90% reliability, how many students would need to be sampled

Answers

Answer:

6546 students would need to be sampled.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

The dean randomly selects 200 students and finds that 118 of them are receiving financial aid.

This means that [tex]n = 200, \pi = \frac{118}{200} = 0.59[/tex]

90% confidence level

So [tex]\alpha = 0.1[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].

If the dean wanted to estimate the proportion of all students receiving financial aid to within 1% with 90% reliability, how many students would need to be sampled?

n students would need to be sampled, and n is found when M = 0.01. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.01 = 1.645\sqrt{\frac{0.59*0.41}{n}}[/tex]

[tex]0.01\sqrt{n} = 1.645\sqrt{0.59*0.41}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.59*0.41}}{0.01}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.645\sqrt{0.59*0.41}}{0.01})^2[/tex]

[tex]n = 6545.9[/tex]

Rounding up:

6546 students would need to be sampled.

Find the simplified product:
V9x* - 33x
O
V12x12
о
327x12
O
3x4
O
9.x

Answers

9514 1404 393

Answer:

  (c)  3x^4

Step-by-step explanation:

The applicable rules of exponents are ...

  (a^b)(a^c) = a^(b+c)

  (a^b)^c = a^(bc)

___

  [tex]\displaystyle\sqrt[3]{9x^4}\cdot\sqrt[3]{3x^8}=\sqrt[3]{9\cdot3x^4x^8}=\sqrt[3]{27x^{12}}=\sqrt[3]{(3x^4)^3}=\boxed{3x^4}[/tex]

If someone can pls give me the answer the would be greatly appreciated :)

Answers

Step-by-step explanation:

The Answer Is Provided Below ➳

(2²)² = 2⁴/2⁴ = 2⁰ × 2⁰ = 2⁰/2⁰

I need help, and I can’t figure it out

Answers

Step-by-step explanation:

put the value of f(x)

I think that you know

hope it is helpful for you

Answer:

4x + 2h - 1

Step-by-step explanation:

[tex]\frac{f(x+h) - f(x)}{h}[/tex]

[tex]\frac{(2(x+h)^2 - (x + h) + 5) - (2x^2 - x + 5)}{h}[/tex]

[tex]\frac{2x^2 + 4xh + 2h^2 - x - h + 5 - 2x^2 + x - 5}{h}[/tex]

[tex]\frac{4xh + 2h^2 - h}{h}[/tex]

4x + 2h - 1

Ellis makes some biscuits. For every 200g of flour he uses, he needs 75g of butter
a. Write a ratio for the amount of flour to the amount of butter.
b. Write a formula forf, the amount of flour, in terms of the amount of butter, b.
c. Ellis makes 24 biscuits using 300g of flour.
How many biscuits can he make with 375g of butter?

Answers

Answer:

a) 8:3, b) no formula is there, c) 30

Step-by-step explanation:

because 200/75=8:3

because there formula being obtained

because 300/24=12.5

375/12.5=30

Write an equation of the line that passes through the point (4, –5) with slope 2.
A. y−4=−2(x+5)
B. y+5=−2(x−4)
C. y+5=2(x−4)
D. y−4=2(x+5)

Answers

It’s C, y + 5 = 2(x - 4).

In y = mx + b form:
y = 2x - 13

Which one is a better deal?
paying $2.88 for a 12 roll package of toilet paper
paying $1.20 for a 6 roll package of toilet paper

Answers

Answer:

paying $1.20 for a 6 roll package of toilet paper

Step-by-step explanation:

to find the answer, double 6 to equal 12 and double the price as well. therefore, it is 2.40. since 2.40 is cheaper than 2.88, it is a better deal.

Answer:

paying $1.20 for a 6 roll package

Step-by-step explanation:

$2.88 divided by 12 = $0.24
$1.20 divided by 6 = $0.20

Hence, i think the best deal is paying $1.20 for a 6 roll package

What are the coordinates of the terminal point for 8 = 330°?
1
A.
-
I
22
1
V3
O B.
2
V3
1
O c.
2
D.
1 3
2 2

Answers

Answer:

Step-by-step explanation:

If you plot this angle in the coordinate plane, you will find yourself in the fourth quadrant with a referencew angle of 30. Constructing the triangle from that reference angle and using the Pythagorean triple for a 30-60-90 triangle, you get that the side adjacent to the reference angle is √3, the side opposite the reference angle is a -1, and the hypotenuse (which is NEVER negative!) is 2. The x and y coordinates of the terminal point result from the cos (related to the x coordinate) and the sin (related to the y coordinate). The cos of 30:

[tex]cos(30)=\frac{\sqrt{3} }{2}[/tex] and the sin of 30:

[tex]sin(30)=-\frac{1}{2}[/tex] so the coordinates of the terminal point on that angle are

[tex](\frac{\sqrt{3} }{2},-\frac{1}{2})[/tex]

You could also just go to your unit circle, find the angle 330 and look at the coordiantes they give you there for (cos, sin). But I'm a high school math teacher so I wanted you to know how to find this outside of the unti circle. Cuz what if you lost it!?

Trapezoid A B C D is shown. A diagonal is drawn from point B to point D. Sides B C and A D are parallel. Sides B A and C D are congruent. Angle C B D is 24 degrees and angle B A D is 116 degrees.
What is the measure of angle ABD in trapezoid ABCD?

24°
40°
64°
92°

Answers

Answer:

40 degrees un edge

Step-by-step explanation:

Answer:

The person above me got this correct, so the answer to this is 40! I just did the Unit Test and got a 100%!

Which choice is equivalent to √3 *√8*√5
A. 2√30
B. 4√30
C. 10√12
D. 24√5

Answers

[tex]\implies {\blue {\boxed {\boxed {\purple {\sf { A. \:2 \sqrt{30} }}}}}}[/tex]

[tex]\sf \bf {\boxed {\mathbb {STEP-BY-STEP\:EXPLANATION:}}}[/tex]

[tex] = \sqrt{3} \times \sqrt{8} \times \sqrt{5} [/tex]

[tex] = \sqrt{3 \times 2 \times 2 \times 2 \times 5} [/tex]

[tex] = \sqrt{ ({2})^{2} \times 2 \times 3 \times 5} [/tex]

[tex] = 2 \sqrt{2 \times 3\times 5} [/tex]

[tex] = 2 \sqrt{30} [/tex]

Note:

[tex] \sqrt{ ({a})^{2} } = a[/tex]

[tex]\bold{ \green{ \star{ \orange{Mystique35}}}}⋆[/tex]

Answer:

A. 2√30

Step-by-step explanation:

[tex] \small \sf \: \sqrt{3} \times \sqrt{8} \times \sqrt{5} \\ [/tex]

split √8

[tex] \small \sf \leadsto \sqrt{3 × 2 × 2 × 2 × 5} [/tex]

[tex] \small \sf \leadsto \: 2 \sqrt{2 \times 3 \times 5} [/tex]

[tex] \small \sf \leadsto \: 2 \sqrt{30} [/tex]

Couch johnson needs to buy shirts for his soccer players. He finds a package of 2:shirts for 16.00. How much will it cost to buy 18 shirts?

Answers

Answer:

144

Step-by-step explanation:

We can write this as 2 shirts = 16.00 . Then, we can write this as a ratio, where

2 shirts / 16.00 = 18 shirts/ cost of 18 shirts as the cost for a pair of shirts remains the same, so the ratio will as well.

Therefore, writing the cost of 18 shirts as c, we have

2 shirts/16.00 = 18 shirts/c

multiply both sides by c to remove a denominator

2 shirts * c/16.00 = 18 shirts

multiply both sides by 16 to remove the other denominator

2 shirts * c = 18 shirts * 16

divide both sides by 2 shirts to isolate the c, as we want to figure that out

c = 18 shirts * 16/2 shirts

c=144

will give brainyest (m^2/3 n^-1/3)^6

Answers

Step-by-step explanation:

here is the answer to your question

A man had 35 goats.he sold 10 of
them.how many did he remains with.

Answers

Answer:

He remained with 25 goats.

Step-by-step explanation:

35 - 10 = 25

Hope this helps.

Answer:

He remained with 25 goats

Step-by-step explanation:

35 - 10 = 25

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