Consumer Reports indicated that the average life of a refrigerator before replacement is 14 years with a standard deviation of 2.5 years. Assume the age a refrigerator is replaced is normally distributed.
A.) State the random variable
B.) What is the probability that someone will keep a refrigerator fewer than 11 years before replacement?
C.) What is the probability that someone will keep a refrigerator more than 18 years before replacement?
D.) What is the probability that someone will replace a refrigerator between 8 and 15 years?
E.) Suppose a company guarantees refrigerators and will replace a refrigerator that breaks while under guarantee with a new one. However, the company does not want to replace more than 5% of the refrigerators under guarantee. For how long should the guarantee be made (rounded to the nearest tenth of a year)?
F.) If it turns out that 40$ of all new refrigerators need to be replaced withing 10.5 years, is there an issue with the manufacturing process? Have some numbers to back up your reasoning.

Answers

Answer 1

Answer:

a.) Average life of a refrigerator

b.) 0.1151

c.) 0.0548

d.) 0.6472225

Step-by-step explanation:

Given that :

Average life before replacement, mean, m = 14 years

Standard deviation, σ = 2 years

A.)

The random variable is the variable which is being measured.

B.) What is the probability that someone will keep a refrigerator fewer than 11 years before replacement?

Fewer than 11 years, P(x < 11)

We need to obtain the Z probability, at P(Z < 11)

The Zscore = (x - mean) / standard deviation

Zscore = (11 - 14) / 2.5 = - 1.2

P(Z < - 1.2) = 0.1151

C.) What is the probability that someone will keep a refrigerator more than 18 years before replacement?

More than 18 years, P(x > 18)

We need to obtain the Z probability, at P(Z > 18)

The Zscore = (x - mean) / standard deviation

Zscore = (18 - 14) / 2.5 = 1.6

P(Z > 1.6) = 0.0548

D.) What is the probability that someone will replace a refrigerator between 8 and 15 years?

P(x < 8)

The Zscore = (x - mean) / standard deviation

Zscore = (8 - 14) / 2.5 = - 2.4

P(Z < - 2.4) = 0.0081975

P(x < 15)

The Zscore = (x - mean) / standard deviation

Zscore = (15 - 14) / 2.5 = 0.4

P(Z < 0.4) = 0.65542

P(Z < 0.4) - P(Z < - 2.4)

0.65542 - 0.0081975 = 0.6472225


Related Questions

Please help quickly I really don’t understand this question and i’m freaking out.

Answers

Answer:

[tex] \frac{4 \sqrt{3x} }{9} [/tex]

Step-by-step explanation:

[tex] \frac{4 \sqrt{ {21x}^{2} } }{3 \sqrt{63x} } [/tex][tex] \frac{4 \sqrt{ \frac{21 {x}^{2} }{63x} } }{3} [/tex][tex] \frac{4 \sqrt{ \frac{x}{3} } }{3} [/tex][tex] \frac{4 \sqrt{ \frac{x \times 3}{3} } }{3} [/tex][tex] \frac{\frac{4 \sqrt{3x} }{3} }{3} [/tex][tex] \frac{4 \sqrt{3x} }{3} \times \frac{1}{3} [/tex][tex] \frac{4 \sqrt{3x} }{9} [/tex]Hope it is helpful...


A triangular prism has a base area of 12 square centimeters, and a height of 15 centimeters. What is the volume?

Answers

Answer: 180cm^2

Volume=Area is the base • height
Volume=12•15
Volume=180cm^2

Explanation: Since the area of the base is already given, plug in 12 for the base and 15 for the height, then solve. If the area of the base wasn’t given, use the area formula for a triangle (A=(1/2)bh).

In ATUV, the measure of _V=90°, VU = 84, TV = 13, and UT = 85. What ratio
represents the cotangent of _T?
U
85
84
T
13

Answers

Tyyyyyy llama I love you I love the way you are the best friend I love you I love the

Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ= 7. Compute the probability.

Answers

Complete question is;

Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ = 7. What is the probability P (X > 42)?

Answer:

P(X > 42) = 0.1271

Step-by-step explanation:

We are given;

mean; μ = 50

Standard deviation; σ = 7

Formula for the z-score is;

z = (x - μ)/σ

Thus;

z = (42 - 50)/7

z = -1.14

Since we are looking for P (X > 42), then let's look up this z-value from the z-distribution table attached.

We have;

P(X > 42) = 0.1271



A company's mean salary is $65,000 with a standard deviation of $6,000. If a sample of
40 employees is taken, determine the standard error.
948.68
325.25
9328.71
none of these



Answers

Answer:

umm not sure on this one either 9328.71

Step-by-step explanation:

Find the equation of a line perpendicular to x+5y=−2 that contains the point (3,0).

Answers

Perpendicular Definition:

[tex] \large \boxed{m_1m_2 = - 1}[/tex]

Slopes of two different equations multiply each others and must equal to -1. We can also say that the perpendicular occurs only if both equations are negative reciprocal to each others. For example, we are given the equation of y = 2x. The perpendicular to y = 2x would be y = (-1/2)x. See how both are reciprocal to each others.

From the equation below:

[tex] \large{x + 5y = - 2}[/tex]

Since the equation is in the form of Ax+By = C. It is better to use the another slope formula which is:

[tex] \large \boxed{m = - \frac{A}{B} }[/tex]

From the equation above, use the slope formula to find the slope.

[tex] \large{m = - \frac{1}{5} }[/tex]

Therefore the equation has a slope of -1/5. Next to find the perpendicular equation to the original equation. Since our slope is -1/5 - that means the negative reciprocal of -1/5 is 5. Therefore the slope of perpendicular line is 5.

Next we will be using the point-slope form below:

[tex] \large \boxed{y - y_1 = m(x - x_1)}[/tex]

Given the y1 and x1 or (x1,y1) are the points. Our perpendicular slope is 5 which passes through the point (3,0). Substitute both slope and the point in.

[tex] \large{y - 0 = 5(x - 3)}[/tex]

Simplify in the slope-intercept form as we get:

[tex] \large{y = 5x - 15}[/tex]

Answer

y = 5x-15 is perpendicular to x+5y = -2

Hope this helps and let me know if you have any doubts!

2. The set {0,1,-1} is closed under the operation of?

Answers

The set {−1,0,1} is closed under multiplication

2) What is the probability you roll an odd number on a six-
sided die ?

Answers

Answer:

1/2 or 0.5

Step-by-step explanation:

All possible odd values on a 6-sided die include 1, 3, and 5; that is 3 values out of 6 total values. 3/6 or 1/2 is a 0.5 probability.

Helpppppppppppppp:))))

Answers

Given:

Principal value = $1500

Rate of interest = 7% per annum compounded daily

Time = 2 years.

To find:

The amount after 2 years.

Solution:

Formula for amount:

[tex]A=P\left(1+\dfrac{r}{n}\right)^{nt}[/tex]

Where, P is principal, r is the rate of interest in decimals, n is the number of time interest compounded in an year and t is the number of years.

We know that 1 year is equal to 365 days and the interest compounded daily. So, n=365.

Substituting [tex]P=1500,\ r=0.07,\ n=365,\ t=2[/tex] in the above formula, we get

[tex]A=1500\left(1+\dfrac{0.07}{365}\right)^{365(2)}[/tex]

[tex]A=1500\left(\dfrac{365+0.07}{365}\right)^{730}[/tex]

[tex]A=1500\left(\dfrac{365.07}{365}\right)^{730}[/tex]

Using calculator, we get

[tex]A\approx 1725.39[/tex]

The amount after two years is $1,725.39. Therefore, the correct option is (c).

In ABC, c=66,m∠A=3230', and m∠C=11140'. Find the length of side a to the nearest tenth.

Answers

y
=

2
x
+
5
y
=
-
2
x
+
5
Use the slope-intercept form to find the slope and y-intercept.
Tap for more steps...
Slope:

2
-
2
y-intercept:
(
0
,
5
)
(
0
,
5
)
Any line can be graphed using two points. Select two
x
x
values, and plug them into the equation to find the corresponding
y
y
values.
Tap for more steps...
x
y
0
5
5
2
0

how are they the same

Answers

Answer:

Step-by-step explanation:

The ways that they are the same are.

The slope is the same.Since the slope is the same for both of them, there is no possible solution meant for both of them. The slope is 1/4They are both written in slope y intercept form.The only difference is the y intercept is different. y intercept for y = 1/4 x is 0,0y intercept for y = 1/4 x is 0,5

What is an opposite number?

Answers

Answer:

The opposite of a number is the number on the other side of 0 number line, and the same distance from 0.

my last question 30 pts plzzzzzzzzz help
An expression is shown below:

4(m + 3 + 5m)

Part A: Write two expressions that are equivalent to the given expression. (3 points)

Part B: Show that one of your expressions in Part A is equivalent to the given expression using algebraic properties. Explain which properties you used. (4 points)

Part C: Show that your other expression from Part A is equivalent to the given expression by substituting a number for m. (3 points)

Answers

Answer:

A) 48m + 12 and 3(2m + 4 + 14m)

B) 48m + 12 is equivalent to 6(m + 2 + 7m) because if you distribute the 6 to everything inside the parentheses, you get 6m + 12 + 42m. This can be simplified further by adding 6m and 42m together, leaving you with 48m + 12.  

C) m = 2

6(m + 2 + 7m)

6[2 + 2 + 7(2)]

6(4 + 14)

6(18) 1

108

3(2m + 4 + 14m)

3[2(2) + 4 + 14(2)]

3(4 + 4 + 28)

3(8 + 28) 3

(36) 108

108 = 108  

Giving out brainliestttt answer !!! help me out?!!!

Answers

Answer:

F= 60.256

D = 29.744

Step-by-step explanation:

This is a completely different from the way usually I do it

B = arcsin(b·sin(A)a)

= 1.05166 rad = 60.256°

180-60.256-90 = 29.744°

A box contains 15 green marbles and 16 white marbles. If the first marble chosen was a white marble, what is the probability of choosing, without replacement, another white marble

Answers

Answer:  8/31

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

Explanation:

16/31 represents the probability of picking a white marble

This is because there are 16 white out of 15+16 = 31 total.

---------

After we make a first selection, we have 16-1 = 15 white marbles left out of 31-1 = 30 marbles overall. The probability of selecting another white marble is 15/30 = 1/2.

Multiply those two fractions:

(16/31)*(1/2) = (16*1)/(31*2) = (2*8)/(31*2) = 8/31

which represents the probability of selecting two white marbles in a row, such that we don't put the first one back (and there's no replacement).

You buy a used car for $9,000. The car depreciates 9% per year. Find the value of the
car after 10 years.

Answers

Answer:

$19,000.

Step-by-step explanation:

#hopeithelpsbrainliest me.

A balloon is 4 ft above the ground. It is released and floats up 3 ft
every second. Write an equation to model the height of the balloon
as a function of time in seconds. Write your answers in the blanks.

Answers

Answer:

4+(3 times x)= height of balloon.   x = seconds

Step-by-step explanation:

I hope this helps you! :D

A school cafeteria wants to survey a random sample of 50 students about the quality of food. During one lunch period, every 5th student who walks through the cafeteria door is surveyed until 50 students are selected. Which of the following statements is true about this sample?

Answers

Answer:

B

Step-by-step explanation:

Answer:

B EDGE

Step-by-step explanation:

Find the median and mean of the data set below:
10, 43, 20, 11

Answers

Median: 10.5
Mean: 21

A point particle with charge q is at the center of a Gaussian surface in the form of a cube. The electric flux through any one face of the cube is: _________.
i. q/E0
ii. q/E4Ï€E0
iii. q/4E0
iv. q/6E0
v. q/16E0

Answers

Answer:

iv. q/6E0

Step-by-step explanation:

Electric flux formula:

The electic flux formula, of a charge q is given by, through an entire cube, is given by:

[tex]E = \frac{q}{E_o}[/tex]

In which [tex]E_o[/tex] is a constant related to the material.

The electric flux through any one face of the cube is:

Key-word is face, and a cube has 6 faces, with the force distributed evenly throughout it. Thus

[tex]E_f = \frac{1}{6} \times \frac{q}{E_o} = \frac{q}{6E_o}[/tex]

And the correct answer is given by option iv.

Which system of equations represents the matrix shown below?

Answers

Answer:

c

Step-by-step explanation:

A journal article reports that 34% of fathers take no responsibility for child care. A group of fathers believes that this estimate is too high. In a random sample of 80 fathers, it was found that 23 of those fathers take no responsibility for child care. Is there significant evidence at the 1% significance level that less than 34% of fathers take no responsibility for child care

Answers

Answer:

The p-value of the test is 0.1611>0.01, which means that there is not significant evidence at the 1% significance level that less than 34% of fathers take no responsibility for child care

Step-by-step explanation:

A journal article reports that 34% of fathers take no responsibility for child care. A group of fathers believes that this estimate is too high.

At the null hypothesis, we test if the proportion is of at least 34%, that is:

[tex]H_0: p \geq 0.34[/tex]

At the alternative hypothesis, we test if the proportion is less than that, that is:

[tex]H_1: p < 0.34[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.34 is tested at the null hypothesis:

This means that [tex]\mu = 0.34, \sigma = \sqrt{0.34*0.66}[/tex]

In a random sample of 80 fathers, it was found that 23 of those fathers take no responsibility for child care.

This means that [tex]n = 80, X = \frac{23}{80} = 0.2875[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.2875 - 0.34}{\frac{\sqrt{0.34*0.66}}{\sqrt{80}}}[/tex]

[tex]Z = -0.99[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion below 0.2875, which is the p-value of Z = -0.99.

Looking at the Z-table, Z = -0.99 has a p-value of 0.1611.

The p-value of the test is 0.1611>0.01, which means that there is not significant evidence at the 1% significance level that less than 34% of fathers take no responsibility for child care

Suppose we are interested in bidding on a piece of land and we know one other bidder isinterested. The seller announced that the highest bid in excess of $10,000 will be accepted.Assume that the competitor’s bid x is a random variable that is uniformly distributedbetween $10,000 and $15,000.a. Suppose you bid $12,000. What is the probability that your bid will be accepted?b. Suppose you bid $14,000. What is the probability that your bid will be accepted?c. What amount should you bid to maximize the probability that you get theproperty?d. Suppose you know someone who is willing to pay you $16,000 for the property. Wouldyou consider bidding less than the amount in part (c)? Why or why not?

Answers

Answer:

a. 0.4 = 40% probability that your bid will be accepted

b. 0.8 = 80% probability that your bid will be accepted.

c. $15,000.

d. Bidding $15,000 guarantees you a profit of $1,000, while trying to bid less than $15,000, you can end up without a profit, thus, you should not consider bidding less than the amount in part (c).

Step-by-step explanation:

Uniform probability distribution:

An uniform distribution has two bounds, a and b.

The probability of finding a value of at lower than x is:

[tex]P(X < x) = \frac{x - a}{b - a}[/tex]

Assume that the competitor’s bid x is a random variable that is uniformly distributed between $10,000 and $15,000.

This means that [tex]a = 10, b = 15[/tex], considering the measures in thousands of dollars.

a. Suppose you bid $12,000. What is the probability that your bid will be accepted?

Probability that the other bidder's bid is less than 12000(X < 12). So

[tex]P(X < 12) = \frac{12 - 10}{15 - 10} = \frac{2}{5} = 0.4[/tex]

0.4 = 40% probability that your bid will be accepted.

b. Suppose you bid $14,000. What is the probability that your bid will be accepted?

Probability that the other bidder's bid is less than 14000(X < 14). So

[tex]P(X < 14) = \frac{14 - 10}{15 - 10} = \frac{4}{5} = 0.8[/tex]

0.8 = 80% probability that your bid will be accepted.

c. What amount should you bid to maximize the probability that you get the property?

The upper bound of the uniform distribution, that is, $15,000.

d. Suppose you know someone who is willing to pay you $16,000 for the property. Would you consider bidding less than the amount in part (c)? Why or why not?

Bidding $15,000 guarantees you a profit of $1,000, while trying to bid less than $15,000, you can end up without a profit, thus, you should not consider bidding less than the amount in part (c).

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 511 human resource​ professionals, each was asked about the importance of the age of a job applicant. The survey subjects were randomly selected by pollsters from a reputable market research firm.
a) it is flawed because it is a census.
b) it is flawed because it is not statistically significant.
c) it appears to be sound because the data are not biased in anyway.
d) it is flawed because it is a voluntary response sample.

Answers

Answer:

c) it appears to be sound because the data are not biased in anyway.

Step-by-step explanation:

From the information given regarding the sample selection method , the size, the larger sample from which the survey subject were selected, we can conclude that the data is sound and not in anyway biased. The subject were selected from a reputable market research firm, which means the subjects were chosen from a larger sample which is reliable and not just a voluntary pool of subjects. Also, the selection process is randomized. Based on these, there are no flaws which are likely to cause the introduction of bias into the sample selected. Hence, the data is sound and not in any way biased.

Ordena de mayor a menor el siguiente grupo de fracciones y decimales

-2,14; 7/50; -2,41; -11/8; -2,1

Answers

Answer:

-2.41: -2.14: -2.1: -11/8: 7/50

How many 1/6 cup servings of. Rice are in 2/3 cup of rice

Answers

9514 1404 393

Answer:

  4

Step-by-step explanation:

2/3 = 4/6

There are four 1/6-cup servings of rice in 4/6 cups of rice.

Can you help me please

Answers

Answer:

no solution

Step-by-step explanation:

[tex]\dfrac{2x - 6}{4} > \dfrac{x - 3}{2}[/tex]

The LCD is 4, so multiply both sides of the inequality by 4.

[tex]4 \times \dfrac{2x - 6}{4} > 4 \times \dfrac{x - 3}{2}[/tex]

[tex]2x - 6 > 2 \times (x - 3)[/tex]

[tex]2x - 6 > 2x - 6[/tex]

Subtract 2x from both sides.

[tex]-6 > -6[/tex]

Since -6 = -6, the above statement is false, so there are no solutions.

Answer: no solution

mike is looking at the roof of a new house from the front. he notices that the roof is triangular in shape with a base 11.2m. the left side is 6.7m long and makes an angle of 72 degree with the base of the roof. if this is the only known information, determine the angle the right side of the roof makes with the base of the roof to the nearest degree. be sure to first make a sketch

Answers

Answer:

35°

Step-by-step explanation:

From the sketch made, to obtain B we use the cosine angle formula :

We have 2 so des and an included angle

Cos B = (a² + c² - b²) / 2ac

First we obtain the side c

c² = a² + b² - 2ab CosC

c² = 11.2² + 6.7² - 2(11.7 * 6.7) * cos 72

c = 11.13

Using the value of c

Cos B = (a² + c² - b²) / 2ac

CosB = (11.2² + 11.13² - 6.7²) / (2*11.2*11.13)

Cos B = 204.4269 / 249.312

B = Cos^-1(204.4269 / 249.312)

B = 34.9°

A stadium's normal ticket price is $78. As a special promotion they offer 15% off. What is the price of the discounted
ticket?

Answers

Answer:

$66.3

Step-by-step explanation:

price of a ticket without discount = $78

discount  % = 15%

discount amount = ?

price of a discounted ticket = ?

discount amount = discount% of price of a original ticket

=15/100 * $78

=$1170/100

=$ 11.7

price of the discounted ticket = $78 - $11.7

=$66.3

The discounted price of the stadium's normal ticket is  $66.3

What is the percentage?

A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.

Given, A stadium's normal ticket price is $78 and As a special promotion they offer 15% off.

Therefore, The discounted price of the ticket should be (100 - 15)% = 85% of the original price which is,

= (85/100)×78.

= $66.3 is the discounted price.

learn more about percentages here :

https://brainly.com/question/24159063

#SPJ6

Shine has some money in his account.Every Month, he used the same amount of money from his account to pay for his music classes. The table below shows the amount of money left in his account after a certain amount of time, in months:

Option 4) -$45 per month; the amount of money withdrawn per month

Answers

Answer:

Option 4) -$45 per month; the amount of money withdrawn per month.

Step-by-step explanation:

The rate of change is 45. Before he began taking money out to pay for his classes[month 0], he had $190. Since then, every month, $45 have been withdrawn.

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