Please hold The customer care manager at a cell phone company keeps track of how long each help-line caller spends on hold before speaking to a customer service representative. He finds that the distribution of wait times for all callers has a mean of 12.8 minutes with a standard deviation of 7.2 minutes. The distribution is moderately skewed to the right. Suppose the manager takes a random sample of 45 callers and calculates their mean wait time x. What is the shape of the sampling distribution of x for samples of size n = 45 from this population? Justify. Calculate the probability that the mean wait time x is more than 15 minutes.

Please hold The customer care manager at a cell phone company keeps track of how long each help-line caller spends on hold before speaking to a customer service representative. He finds that the distribution of wait times for all callers has a mean of 12.8 minutes with a standard deviation of 7.2 minutes. The distribution is moderately skewed to the right. Suppose the manager takes a random sample of 45 callers and calculates their mean wait time x. What is the shape of the sampling distribution of x for samples of size n = 45 from this population? Justify. Calculate the probability that the mean wait time x is more than 15 minutes.

Name: Please hold The customer care manager at a cellphone company keeps tr
Uploaded: 2024-03-20T07:07:12.000Z
Channel: Bartleby
Description: Please hold The customer care manager at a cellphone company keeps track of how long eachhelp-line caller spends on hold before speaking toa customer service representative. He finds that thedistribution of wait times for all callers has a meanof 12

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

Suppose a new drug is intended to improve walking distance in patients with Parkinson’s Disease. A researcher measures patients’ walking distance in feet before and after trying the drug for 9 weeks. What type of statistical test
You may need to use the appropriate technology to answer this question. Data were collected on the top 1,000 financial advisers. Company A had 239 people on the list and another company, Company B, had 121 people on the list. A sample of 16 of the advisers from Company A and 10 of the advisers from Company B showed that the advisers managed many very large accounts with a large variance in the total amount of funds managed. The standard deviation of the amount managed by advisers from Company A was s₁ = $583 million. The standard deviation of the amount managed by advisers from Company B was s₂ = $484 million. Conduct a hypothesis test at a = 0.10 to determine if there is a significant difference in the population variances for the amounts managed by the two companies. What is your conclusion about the variability in the amount of funds managed by advisers from the two firms? State the null and alternative hypotheses. 2 2 H₂:0 2 Find the value of the test statistic. (Round your answer…
Suppose that a recent article stated the mean time spent in jail by a first-time convicted burglar is 2.7 years. A study was then done to see if the mean time has increased in the new century. A random sample of 27 first-time convicted burglars in a recent year was picked. The mean length of time in jail from the survey was 3.01 with a standard deviation of 1.78 years. Assume that the distribution of jail times is approximately normal. Test the claim at the level of significance 0.1. Select one: a) t_stat = 0.9 and t_cr = 1.31 : The mean time increased significantly in the new century b) t_stat = 0.9 and t_cr = 1.31 : The mean time didn’t increase in the new century c) t_stat = 0.99 and t_cr = 1.71 : The mean time didn’t increase in the new century d) t_stat = 0.99 and t_cr = 1.71 : The mean time increased significantly in the new century
A taxi company operates in two different regions, and it is analyzing the prices of rides in those regions. It has compiled the prices (in dollars) of 101 rides in each of the two regions during the last week. The histograms below show the distributions of the two data sets. Each histogram shows price (in dollars) on the horizontal axis and the number of taxi rides on the vertical axis. The means and standard deviations for the data sets are also given. Region A 25- 20+ 15+ 10+ 5+ 1₂ 0.5 5.5 10.5 15.5 20.5 25.5 30.5 35.5 40.5 45.5 50.5 Region A mean: $25.28 Region A standard deviation: $7.95 25 Expl 20- 15+ 10+ neck 5+ 0A 0.5 5.5 5.5 10.5 15.5 20.5 25.5 30.5 35.5 40.5 45.5 50.5 (a) Identify the data set for which it is appropriate to use the Empirical Rule. It is appropriate to use the Empirical Rule for the (Choose one) data set. The company wants to use the Empirical Rule to make some approximations about both data sets. Unfortunately, it is appropriate to use the Empirical Rule on…
The chocolate chip cookies that are produced at Perry’s Cookie Emporium have weights which are approximately normally distributed with the mean weight 180 grams and with standard deviations 20 grams. The cookies, however, are sold by count, not by weight. Perry wants to improve his image, so he decides to set aside lightest 20% of the cookies to be packaged and sold separately. What cookie weight will divide the lightest 20% from the heaviest 80%?
An analyst found that the average amount of money in bank accounts at his/her bank is $2,000 with a standard deviation of $150. What would be the variance?
Suppose that the quarterly sales levels among health care information systems companies are approximately normally distributed with a mean of 8 million dollars and a standard deviation of 1.3 million dollars. One health care information systems company considers a quarter a "failure" if its sales level that quarter is in the bottom 10% of all quarterly sales levels. Determine the sales level (in millions of dollars) that is the cutoff between quarters that are considered "failures" by that company and quarters that are not. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place. 00 0 million dollars X S ? Check acer Q tab esc ! 1 9. a @ 2 W →> S #m 3 X e C d $ LAS 4 C r % 5 f t > < 6 g y & JX b 7 h C n K1300
Can the measure of central tendency tell a researcher how spread out the scores are in a distribution?
A sociologist found that in a sample of 45 retired men, the average number of jobs they had during theirlifetimes was 7.2. The population standard deviation is 2.3(a) Find the best point estimate of the mean.The best point estimate of the mean is
A developmental psychologist is interested in the well-being of older adults living in retirement communities. She samples 10 people living in a retirement community in Florida and finds the following scores on a life satisfaction measure: 23, 25, 16, 26, 29, 24, 21, 20, 22, 24 Compute the mean, median, mode, SS, df, variance, and standard deviation for these scores. Use the table below to aid your calculations and show all work.
A company provides home internet networking services and promises customers to be compensated for a 1 delayed service if the service calls cannot be resolved under an hour. Times for service calls is known to follow a normal distribution with a mean of 65 minutes and standard deviation of 7 minutes. What is the shortest range of service times that includes 25% of all service calls? Type your numerical answer here.
Maddie has two different routes that she can take to get to school. The first route is a longer distance, but has no traffic lights. The second route is a shorter distance, but has a lot of traffic lights. The amount of time it takes to get to school by the "longer distance" route follows a Normal distribution with mean 20 minutes and standard deviation o = 1.5 mirutes. The amount of time it takes to get to school by the "shorter distance" route follows a Normal distribution with mean =17 minutes and standard deviation a = 6.5 minutes. Suppose we select independent random samples of 20 days for each route. Let XL-Xs be the đifference in the sample mean travel time for the two routes %3D %3D (a) Calculate the probability that the sample mean time for the longer distance is shorter than the sample mean time for the shorter distance. (b) Should we be surprised if the sample mean time for the longer distance is shorter than the sample mean time for the shorter distance?