This factored? I know it’s easy but I’m exhausted

The manager of a new supermarket wished to estimate the likely expenditure of his customers. A sample of till slips from a simil

bagirrra123 [75]

Answer:

0.0228 = 2.28% probability that any shopper selected at random spends more than $80 per week.

88.54% of shoppers are expected to spend between $30 and 80 per week.

Step-by-step explanation:

Normal Probability Distribution

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

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Normally distributed with a mean of $50 and a standard deviation of $15.

This means that $\mu = 50, \sigma = 15$

Find the probability that any shopper selected at random spends more than $80 per week?

This is 1 subtracted by the p-value of Z when X = 80. So

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

$Z = \frac{80 - 50}{15}$

$Z = 2$

$Z = 2$ has a p-value of 0.9772

1 - 0.9772 = 0.0228

0.0228 = 2.28% probability that any shopper selected at random spends more than $80 per week.

Find the percentage of shoppers who are expected to spend between $30 and 80 per week?

The proportion is the p-value of Z when X = 80 subtracted by the p-value of Z when X = 30.

X = 80

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

$Z = \frac{80 - 50}{15}$

$Z = 2$

$Z = 2$ has a p-value of 0.9772

X = 30

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

$Z = \frac{30 - 50}{15}$

$Z = -1.33$

$Z = -1.33$ has a p-value of 0.0918

0.9772 - 0.0918 = 0.8854

0.8854*100% = 88.54%

88.54% of shoppers are expected to spend between $30 and 80 per week.

8 0

3 years ago

13. Find the measure of angle 7 if the measure of angle 1 is 84 degrees less than the measure of angle 2. Please explain how you

Vaselesa [24]

Answer:

is not full information!!!!

Step-by-step explanation:

7 0

4 years ago

You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable estimate for the

Vesna [10]

Answer:

A sample size of at least 1,353,733 is required.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

98% confidence level

So $\alpha = 0.02$ , z is the value of Z that has a pvalue of $1 - \frac{0.02}{2} = 0.99$ , so $Z = 2.327$ .

You would like to be 98% confident that you esimate is within 0.1% of the true population proportion. How large of a sample size is required?

We need a sample size of at least n.

n is found when M = 0.001.

Since we don't have an estimate for the proportion, we use the worst case scenario, that is $\pi = 0.5$

So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.001 = 2.327\sqrt{\frac{0.5*0.5}{n}}$

$0.001\sqrt{n} = 2.327*0.5$

$\sqrt{n} = \frac{2.327*0.5}{0.001}$

$(\sqrt{n})^{2} = (\frac{2.327*0.5}{0.001})^{2}$

$n = 1353732.25$

Rounding up

A sample size of at least 1,353,733 is required.

5 0

4 years ago

Which equation has an a-value of 1, a b value of -3 and a c- value of -5?

Vitek1552 [10]

If the answers are in the standard form of a line then it would be -x + (-3x) = -5y. This is because the standard form of a line is written as Ax + Bx = Cy

9 0

3 years ago

PLEASE HELP ASAP!!! WILL MARK BRAINLIEST!

Natasha2012 [34]

Answer:

D.) 12x + 3

Step-by-step explanation: What you have to do, is distribute the 4 inside the parentheses.

6 + 4(3x - 2) + 5

6 + 4(3x) - 4(2) + 5

6 + 12x - 8 + 5 -Now combine your like terms

6 + 12x - 3

12x + 6 - 3

12x + 3

Hope this helps you, and is the right answer.

4 0

3 years ago

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