A wireless company claims that the average of the customers cell phone bill is less than $90.00 per month. A sample of 75 customers reported that their average monthly bill is $84.25 with a standard deviation of $16.03. Test the claim at alpha=0.005
A wireless company claims that the average of the customers cell phone bill is less than...
The average monthly cell phone bill was reported to be $73.00 by the U.S. Wireless Industry. A random sampling of ten large cell phone company found the following monthly cell phone charges yields a sample mean of $78.47 with a population standard deviation of $7.41. At the 0.05 level of significance, can it be concluded that the average monthly cell phone bill differs from $73.00? Question 24 (2.63 points) Which test are you running? One mean z-test Chi-Square Goodness of...
6. An insurance company claims that the average automobile on the road today is less than 4 years old. A random sample of 15 cars had an average age of 5.4 years with a standard deviation of 1.1 years. Assume that the population is normally distributed. Test the claim at ∝= 0.05
DMV claims that their average wait times are less than 15 minutes. A random sample of 10 people had a mean wait time of 13 minutes with a standard deviation of 3.5 minutes. Assuming wait times are normally distributed , test the claim at alpha=0.10 . Hint : One Mean, T-test.
A survey claims that the average cost of a hotel room in Tulsa, Oklahoma, is less than $49.21. In order to test this claim, a researcher selects a sample of 26 hotel rooms and finds the average cost equal to $47.37 with a sample standard deviation of $6.42. Assume the population random variable is normal. At alpha=.1.
An insurance company claims the average car on the road is less than 6 years old. Based on a random sample of 15 cars, the mean age is 5.8 years with a standard deviation of 1.1 years. Does the sample support the insurance company’s claim?
The average single smart phone cell phone bill is now averaging $73 with a standard deviation of $20. What is the probability that a sample mean of 40 produces a sample mean equal to $73?
A bank claims that the mean waiting time in line is less than 4.1 minutes. A random sample of 60 customers has a mean of 4 minutes. Assuming a population standard deviation of 0.6 minute, test the bank's claim with an ? = 0.05 level of confidence. ?0 = ___________________________________ ?? = ___________________________________ Test Statistic = __________________________ Alpha level of significance= __________________ Classical Critical Value = ____________________ P-value = _______________________________ ________Conclusion: A) reject ?0 B) fail to reject ?0 ________Interpretation:...
The average single smart phone cell phone bill is now averaging $73 with a standard deviation of $20. What is the probability that a sample mean of 40 produces a sample mean between $70 and $80?
According to a report, the standard deviation of monthly cell phone bills was $49.64 three years ago. A researcher suspects that the standard deviation of monthly cell phone bills is different from today. (a) Determine the null and alternative hypotheses. (b) Explain what it would mean to make a Type I error. (c) Explain what it would mean to make a Type Il error. (a) State the hypotheses. Ho HY (Type integers or decimals. Do not round.) (b) Explain what...
A marketing manager for a cell phone company claims that more than 35% of children age 10 have cell phones. In a random sample of 5000 it is found that 1805 had cell phones. Can you conclude that the manager's claim is true? Use a significance level a=0.01. Use this scenario to answer questions 16-20. 16) State the alternative and null hypothesis. 17) Calculate the test statistic. 18) Identify the p-value. 19) Make your decision. 20) Interpret the results.