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8_murik_8 [283]
3 years ago
15

The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than av

erage quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.2 years and a standard deviation of 0.6 years. He then randomly selects records on 38 laptops sold in the past and finds that the mean replacement time is 3.9 years. Assuming that the laptop replacement times have a mean of 4.2 years and a standard deviation of 0.6 years, find the probability that 38 randomly selected laptops will have a mean replacement time of 3.9 years or less.
Mathematics
1 answer:
yanalaym [24]3 years ago
5 0

Answer: 0.0010

Step-by-step explanation:

Given the following :

Population Mean(m) = 4.2 years

Sample mean (s) = 3.9

Standard deviation (sd) = 0.6

Number of samples (n) = 38

Calculate the test statistic (z) :

(sample mean - population mean) / (sd / √n)

Z = (3.9 - 4.2) / (0.6 / √38)

Z = (- 0.3) / (0.6 / 6.1644140)

Z = -0.3 / 0.0973328

Z = - 3.0822086

Z = - 3.08

From the z table :

P(Z ≤ - 3.08) = 0.0010

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Ira Lisetskai [31]
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Reduces los números usando el máximo común divisor= 2
6 0
2 years ago
Ms. Lane borrowed $1,000 from her bank for one year at an interest rate of 10 percent. During that year, the price level went up
Lunna [17]

Answer:

Consider the complete question is,

'Ms. Lane borrowed $1,000 from her bank for one year at an interest rate of 10 percent. During that year, the price level went up by 15 percent. Which of the following statements is correct?

a. Ms. Lane will repay the bank fewer dollars than she initially borrowed.

b. Ms. Lane's repayment will give the bank less purchasing power than it originally loaned her.

c. Ms. Lane's repayment will give the bank greater purchasing power than it originally loaned her.

d. Ms. Lane's repayment will give the bank the same purchasing power that it originally loaned her.'  

Solution :

We have,

The borrowed amount, P = $ 1,000,

Interest rate, r = 10% = 0.1,

Time, t = 1 year,

Thus, the returned amount,

A=P(1+r)^t=1000(1+0.1)^1=1000(1.1) = \$ 1100

∵ A > P

⇒ Ms. Lane will repay the bank greater dollars than she initially borrowed.

Now,  the price level went up by 15 percent,

∵ 1000 + 15% of 1000 = 1000 + 150 = 1500

And, 1500 > 1100

⇒ Ms. Lane's repayment will give the bank less purchasing power than it originally loaned her.

8 0
3 years ago
What is the range of the relation shown in the graph?
emmainna [20.7K]

Answer:

-2

Step-by-step explanation:

7 0
3 years ago
The ratio of strawberries to bananas in a smoothie recipe are shown in the graph below.
Lana71 [14]

Answer:

IT is D!

Step-by-step explanation:

Hope this helps!!! ;) <3

7 0
3 years ago
Read 2 more answers
Joe can drive 194 miles in 4 hours. At the same<br> rate, how far can he drive in 6 hours.
goblinko [34]

Answer:

Lets take the miles for 6 hours to be x.

Using cross-multiplication, this problem can be solved.

194              4

x                  6

1164 = 4x

x = 291

Therefore, Joe drives 291 miles in 6 hours.

4 0
3 years ago
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