Question

In: Statistics and Probability

Shake Shack at the mall is a popular destination with long wait times. Suppose we wish...

Shake Shack at the mall is a popular destination with long wait times. Suppose we wish to estimate the wait time for customers at peak dinner time. Assume a previous random sample of size 30 was taken and the sample mean was found to be 14.82 minutes with a sample standard deviation of 4.13 minutes. How large a sample should they take to estimate the true mean wait time to be within 1.2 minutes at the 95% confidence interval?

Solutions

Expert Solution

Given ME = 1.2, Sigma(Standard Deviation) = 4.13, Alpha() = 0.05

The Zcritical at Alpha() = 0.01 is 1.96

The ME is given by :

ME = Z critical * Std Deviation(SD) / Sqrt(n)

Squaring both sides we get: (ME)2 = (Z critical)2 * (SD)2/n

Therefore n = (Zcritical * SD/ME)2 = (1.96*4.13/1.2)2 = 45.5

Therefore n = 46 (Taking it to the next whole number)

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image


Related Solutions

Suppose the average bus wait times are normally distributed with an unknown population mean and a...
Suppose the average bus wait times are normally distributed with an unknown population mean and a population standard deviation of of five minutes. A random sample of 30 bus wait times are taken and has a sample mean of 25 minutes. Find a 95% confidence interval estimate for the population mean wait time.
Dr. Patel is concerned about the long wait times in his office. The following table presents...
Dr. Patel is concerned about the long wait times in his office. The following table presents six random observations for the patient waiting times over a period of 10 days. Observations (mins) Day 1 2 3 4 5 6 1 30 17 18 21 19 33 2 17 11 33 33 39 11 3 19 25 40 17 38 13 4 29 31 29 25 22 21 5 15 34 26 14 14 18 6 8 11 29 33 39...
We wish to compare list prices of six popular drugs for HIV infection. The data in...
We wish to compare list prices of six popular drugs for HIV infection. The data in the table represent means and standard deviations of prices for each drug based on a survey of 55 pharmacies in the New England area. Prices are for a full course of treatment. Generate a graphical display of the mean prices shown in the following table. Mean and Standard Deviation of Prices of Six HIV Drugs Drug Mean Price Standard Deviation in Price A $3,200...
Suppose we are given a set ? containing 2? integers, and we wish to partition it...
Suppose we are given a set ? containing 2? integers, and we wish to partition it into two sets ?1 and ?2 so that |?1 | = |?2 | = ? and so that the sum of the numbers in ?1 is as close as possible to the sum of those in ?2. Let the neighborhood ? be determined by all possible interchanges of two integers between ?1 and ?2. Is ? exact?
An experimenter flips a coin 100 times and gets 62 heads. We wish to test the...
An experimenter flips a coin 100 times and gets 62 heads. We wish to test the claim that the coin is fair (i.e. a coin is fair if a heads shows up 50% of the time). Test if the coin is fair or unfair at a 0.05 level of significance. Calculate the z test statistic for this study. Enter as a number, round to 2 decimal places.
Suppose that we wish to test a claim that a sequence of sample data was produced...
Suppose that we wish to test a claim that a sequence of sample data was produced in a random manner, and suppose that each data value belongs to one of two categories. Let n1n1 be the number of elements in the sequence that belong to the first category, n2n2 be the number of elements in the sequence that belong to the second category, and GG be the number of runs in such a sequence. Answer each of the following questions...
Suppose that we wish to test a claim that a sequence of sample data was produced...
Suppose that we wish to test a claim that a sequence of sample data was produced in a random manner, and suppose that each data value belongs to one of two categories. Let n1 be the number of elements in the sequence that belong to the first category, n2 be the number of elements in the sequence that belong to the second category, and G be the number of runs in such a sequence. Answer each of the following questions...
Suppose that we wish to test a claim that a sequence of sample data was produced...
Suppose that we wish to test a claim that a sequence of sample data was produced in a random manner, and suppose that each data value belongs to one of two categories. Let n1n1 be the number of elements in the sequence that belong to the first category, n2n2 be the number of elements in the sequence that belong to the second category, and GG be the number of runs in such a sequence. Answer each of the following questions...
Suppose we wish to study the effect of education on an individual’s hourly wage using a...
Suppose we wish to study the effect of education on an individual’s hourly wage using a sample of individuals. For each individual i in our sample, let wi denote hourly wage, let ei denote years of post-high school education, let si denote sex (suppose si = 1 for females and si = 0 for males). Consider estimating the relationship: wi = α + βei + ei where α and β are unobservable population parameters and i is the component of...
Suppose that we wish to test whether the population mean of weights of male students at...
Suppose that we wish to test whether the population mean of weights of male students at a certain college to be larger than 68 kilograms. Consider α = 0.05 level of significance and assume normal population. We have a random sample with size 10, x = 70 and s^2 = 10. 1. Complete the test by finding out its critical region and draw your conclusion. 2. Complete the test by finding out its p-value and draw your conclusion. Is your...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT