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4 years ago

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In a random sample of 60 computers, the mean repair cost was $150. Assume the population standard deviation is $36. Construct a

90% confidence interval for the population mean.

2 answers:

kompoz [17]4 years ago

6 0

Answer:

90% confidence interval for the population mean is $149.01,\ 150.99$

Step-by-step explanation:

Given that, in a random sample of 60 computers, the mean repair cost was $150, with the population standard deviation is $36.

Here,

$n=60,\mu=150,\sigma=36$

In case of 90% confidence interval, $Z=1.645$

We know that, the confidence interval will be,

$=\mu\pm Z\dfrac{\sigma}{n}$

Putting all the values,

$=150\pm 1.645\times \dfrac{36}{60}$

$=150\pm 0.987$

$=149.01,\ 150.99$

GaryK [48]4 years ago

3 0

Given that:
x_bar=150, σ=36, n=60
The 90% confidence interval will be found as follows:
+/-1.65(36/sqrt(60))
=+/-1.65(4.64758)
=+/-7.6685
Thus our answer will be:
150+/-7.6685
=157.6685 or 142.3315

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nadya68 [22]

Answer:

$\frac{(\frac{3}{5}*1000) }{6}$

Step-by-step explanation:

First, let's find out how many words Maria has left to write. If she has already finished 2/5 of her essay, she has 3/5ths left to write. We can do 3/5 times 1000 to find out how many words are left.

$\frac{3 }{5} * \frac{1000}{1}$

$\frac{3000}{5}$

$600$

Thus, there are 600 words left to write.

Now to find the amount of time, we can find how take to write 600 words at a pace of 6 words per minute by dividing 600 by 6.

$\frac{600}{6}$

$100$

It will take 100 minutes for Maria to write the rest of her essay. Now let's think about an expression that tells us this information. It sounds like your questions is supposed to have options, but I doesn't seem like you've posted them, no worries however.

So first, the amount she has left to write.

$(\frac{3}{5} * 1000)$

We know this is 600, but we don't have to simplify it for the expression.

Now thinking back to how we found the time, we can divide this '600' by 6.

$\frac{(\frac{3}{5}*1000) }{6}$

This is the expression that shows the amount of time it will take to write the rest of the essay.

$\frac{((1-(\frac{2}{5})*1000) }{6}$ is also a valid solution.

3 0

3 years ago

Read 2 more answers

Please help me thanks enjoy ur points

d1i1m1o1n [39]

400 * 2% = 8

A: 8 * 6 = $48

B: 400 + 48 = $448

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4 years ago

A company is going to make a water tank in the shape of a cylinder. As shown below, the tank will have a height of 4ft and a rad

AleksAgata [21]

First find surface area.

I will skip the exact explanation and just go to it because well its the same concept as the prism.

π*6^2*2+6*2π*4

=72π+48π

=120π

Now we need to take 3.14 for pi getting about

120*3.14=376.8 square foot.

Now the total is 14318.4 dollars, so what's left is simple division.

14318.4/376.8=38

The metal cost 38 dollars per square feet :P

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3 years ago

The output value of a function is represented by P(200). What is the input value for this function?

denis23 [38]

Output = P(200)

Input value = 200

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4 years ago

The dimensions of a closed rectangular box are measured as 60 centimeters, 50 centimeters, and 70 centimeters, with an error in

Studentka2010 [4]

Answer:

The maximum error in calculating the surface area of the box is 72 square centimeters.

Step-by-step explanation:

From Geometry, the surface area of the closed rectangular box ( $A_{s}$ ), in square centimeters, is represented by the following formula:

$A_{s} = w\cdot l + (w + l)\cdot h$ (1)

Where:

$w$ - Width, in centimeters.

$l$ - Length, in centimeters.

$h$ - Height, in centimeters.

And the maximum error in calculating the surface area ( $\Delta A_{s}$ ), in square centimeters, is determined by the concept of total differentials, used in Multivariate Calculus:

$\Delta A_{s} = \left(l+h\right)\cdot \Delta w + \left(w+h\right)\cdot \Delta l + (w+l)\cdot \Delta h$ (2)

Where:

$\Delta w$ - Measurement error in width, in centimeters.

$\Delta l$ - Measurement error in length, in centimeters.

$\Delta h$ - Measurement error in height, in centimeters.

If we know that $\Delta w = \Delta h = \Delta l = 0.2\,cm$ , $w = 60\,cm$ , $l = 50\,cm$ and $h = 70\,cm$ , then the maximum error in calculating the surface area is:

$\Delta A_{s} = (120\,cm + 130\,cm + 110\,cm)\cdot (0.2\,cm)$

$\Delta A_{s} = 72\,cm^{2}$

The maximum error in calculating the surface area of the box is 72 square centimeters.

7 0

3 years ago