6. According to surveys done by the National Retail Federation (NRF) last year, 49.5% of holiday shoppers bought something online during the Cyber Monday sales event. We know the sample proportion (p) would vary for repeated sampling. Let's say that the sampling distribution for (p) is approximately normal with a mean of 0.495 and standard deviation of 0.011. A. Find the probability that at least 0.500 of shoppers bought something online during the Cyber Monday sales. Draw the density curve, be sure to label and shade. B. Find the probability that between 0.485 and 0.515 of shoppers bought something online during the Cyber Monday sales. Draw the density curve, be sure to label and shade.

6. According to surveys done by the National Retail Federation (NRF) last year, 49.5% of holiday shoppers bought something online during the Cyber Monday sales event. We know the sample proportion (p) would vary for repeated sampling. Let's say that the sampling distribution for (p) is approximately normal with a mean of 0.495 and standard deviation of 0.011. A. Find the probability that at least 0.500 of shoppers bought something online during the Cyber Monday sales. Draw the density curve, be sure to label and shade. B. Find the probability that between 0.485 and 0.515 of shoppers bought something online during the Cyber Monday sales. Draw the density curve, be sure to label and shade.

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Joan’s finishing time for the Bolder Boulder 10K race was 1.67 standard deviations faster than the women’s average for her age group. There were 415 women who ran in her age group. Assuming a normal distribution, how many women ran faster than Joan?
Phyllis, a college business student wants to study how many students in her class study for less than 20 hours per week. Past data reveals that the hours college students study per week has a mean of 29 with standard deviation 9 hours. The normal distribution for the population is shown by the dotted black line. She plans to take a random sample of 36 such college students and will calculate the mean hours studying to compare to the known hours studying. Compute the the mean and standard deviation of the sampling distribution of sample means for a sample of size 36. Round your answers to the nearest tenth. Show your answer by moving the two draggable points to build the sampling distribution.
Suppose that water usages in American showers are normally distributed, with an average shower using 20 gallons, and a standard deviation of 3.2 gallons. Estimate the percentage of showers that used (a) between 13.6 and 26.4 gallons. % (b) more than 26.4 gallons. % (c) less than 10.4 gallons. % (d) between 16.8 and 29.6 gallons. %
A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 100 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $52. Complete parts (a) and (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $51? (Use a 0.01 level of significance.) State the null and alternative hypotheses. Ho: H (Type integers or decimals. Do not round. Do not include the $ symbol in your answer.) Identify the critical value(s). The critical value(s) is/are (Type an integer or a decimal. Round to two decimal places as needed. Use a comma to separate answers as needed.) Determine the test statistic. The test statistic, 1STAT, is (Type an integer or a decimal. Round to two decimal places as needed.) State the conclusion. Ho. There is evidence that the…
Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.
Last year, a person wrote 118 checks. Let the random variable x represent the number of checks he wrote in one day, and assume that it has a Poisson distribution. What is the mean number of checks written per day? What is the standard deviation? What is the variance?
pizza delivery chain advertises that it will deliver your pizza in 35 minutes from when the order is placed. Being a skeptic, you decide to test and see if the mean delivery time is actually more than 35 minutes. For the simple random sample of 7 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 39.4 minutes with a standard deviation of 5.5 minutes. Assume that the population distribution is approximately normal. Perform a hypothesis test using a 0.025 level of significance. Step 3 of 3 : Draw a conclusion and interpret the decision.
Suppose that a study of elementary school students reports that the mean age at which children begin reading is 5.3 years with a standard deviation of 0.7 years. If a sampling distribution is created using samples of the ages at which 31 children begin reading, what would be the standard deviation of the sampling distribution of sample means?? Round to 2 decimal places if necessary.
Suppose the number of hours of sleep a person gets per night follows a normal distribution with a mean of 7 hours and a standard deviation of 1.5 hours. What is the probability that a randomly selected person gets between 6 and 8.5 hours of sleep per night? If the top 10% of people who get the most sleep are considered "long sleepers," what is the minimum number of hours of sleep per night required to be a long sleeper?
The daily number of bad checks received by a large department store in a random sample of 5 days out of the past year was 67, 76, 72, 84, and 76. Find the Standard deviation.
The manager at a drive through has implemented a new process and wants to check if the new drive through process has a mean less than 188.83 seconds. The overall std. deviation of all the stores across the globe is 20 seconds. He has taken a sample of 39 and found the mean time to be 186.90 seconds. What does the hypothesis test lead to? Is there evidence to suggest the process has really improved?