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3 years ago

5

Ashley's Internet service is terribly unreliable. In fact, on any given day, there is a 15% chance that her Internet connection

will be lost at some point that day. What is the probability that her Internet service is not broken for five days in a row

1 answer:

stepan [7]3 years ago

6 0

Answer:.3 .3 .3 .3 .3 *.3 = .0007

Step-by-step explanation:

You might be interested in

What is 1 hundredth + 3 tenths=

musickatia [10]

Answer is 0.31. Hope this helps.

6 0

3 years ago

Chuanxi planned a rectangular sidewalk with a length of 21 ft. He made a scale drawing using a scale factor of 1 in. = 7 ft. He

Masteriza [31]

Original Ratio of 1 in = 7 ft so 3 in = 21 ft
Now, New ratio 1 in = x ft so 3 in = 27ft

1/x = 3/27

cross multiply a/b = c/d ad = bc
1/x = 3/27
3x = 27
x = 9

1 in represents 9 ft

7 0

4 years ago

Read 2 more answers

A study of the amount of time it takes a mechanic to rebuild the transmission for a 1992 Chevrolet Cavalier shows that the mean

Dovator [93]

Answer:

B) 0.0069

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 normally distributed samples are 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.

Central Limit Theorem

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

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

In this question, we have that:

$\mu = 8.4, \sigma = 1.8, n = 40, s = \frac{1.8}{\sqrt{40}} = 0.2846$

Find the probability that their mean rebuild time exceeds 9.1 hours.

This is 1 subtracted by the pvalue of Z when X = 9.1. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{9.1 - 8.4}{0.2846}$

$Z = 2.46$

$Z = 2.46$ has a pvalue of 0.9931

1 - 0.9931 = 0.0069

So the answer is B.

6 0

3 years ago

(Figure is provided below)

DanielleElmas [232]

Answer:

The measure of ∠z = 137°

Step-by-step explanation:

Here, angle 1 = 43°

To find : ∠z

Straight line Angle: The angle which measures exactly 180° and is extended by a point on a straight line is called straight angle.

According to the given figure:

∠1 + ∠z = 180 ° (STRAIGHT LINE ANGLE)

or, ∠z = 180 ° - 43° = 137°

Hence, the measure of ∠z = 137°.

7 0

3 years ago

Paint manufacturer uses a machine to fill 1- gallon cans with paint- they want to estimate the mean volume of paint the machine

Triss [41]

Answer:

$n=(\frac{1.64(0.85)}{0.25})^2 =31.09$

So the answer for this case would be n=32 rounded up to the nearest integer

Step-by-step explanation:

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=0.85$ represent the sample standard deviation

n represent the sample size (variable of interest)

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

And on this case we have that ME =0.25 and we are interested in order to find the value of n, if we solve n from equation (1) we got:

$n=(\frac{z_{\alpha/2} s}{ME})^2$ (2)

The critical value for 90% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.05,0,1)", and we got $z_{\alpha/2}=1.64$ , replacing into formula (2) we got:

$n=(\frac{1.64(0.85)}{0.25})^2 =31.09$

So the answer for this case would be n=32 rounded up to the nearest integer

5 0

3 years ago