Question

In: Statistics and Probability

According to a​ report, the mean of monthly cell phone bills was ​$49.32 three years ago....

According to a​ report, the mean of monthly cell phone bills was ​$49.32 three years ago. A researcher suspects that the mean 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 II error.

Solutions

Expert Solution


Related Solutions

According to a​ report, the mean of monthly cell phone bills was $49.33three years ago. A...
According to a​ report, the mean of monthly cell phone bills was $49.33three years ago. A researcher suspects that the mean 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 II error. ​(a) State the hypotheses. H0​: p, μ, σ___?____, >,≠,=,<____?____, $_______ H1​: p, μ, σ___?____, >,≠,=,<____?____, $_______ ​(Type integers or...
According to CTIA-The Wireless Association, the mean monthly cell phone bill in 2018 was $60.64. A...
According to CTIA-The Wireless Association, the mean monthly cell phone bill in 2018 was $60.64. A market researcher believes that the mean monthly cell phone bill has increased today. a) What would be the null and alternative hypothesis for testing whether the mean monthly cell phone bill today has increased since 2018? b) Calculate the P-Value if the researcher phones a random sample of 40 cell phone subscribers and gets a sample average of $67.45 with a sample standard deviation...
According to a report by Scarborough Research, the average monthly household cellular phone bill is $73....
According to a report by Scarborough Research, the average monthly household cellular phone bill is $73. Suppose local monthly household bills are normally distributed with a standard deviation of $11.35. (a) What is the probability that a randomly selected monthly cellphone bill is between $60 and $74? (b) What is the probability that a randomly selected monthly cellphone bill is between $79 and $88? (c) What is the probability that a randomly selected monthly cellphone bill is no more than...
According to a recent report, the US cell phone market has the following market share information:...
According to a recent report, the US cell phone market has the following market share information: Apple (43.9%); Samsung (28.4%); LG (9.7%); Motorola (4.8%); and HTC (3%). Explain the various ways Samsung as a challenger can target competitors established in the market.
A cell phone company states that the mean cell phone bill of all their customers is...
A cell phone company states that the mean cell phone bill of all their customers is less than $83. A sample of 19 customers gives a sample mean bill of $82.17 and a sample standard deviation of $2.37. At ? = 0.05 , test the company’s claim? 1). State the hypothesis and label which represents the claim: : H 0 : H a 2). Specify the level of significance  = 3). Sketch the appropriate distribution, find and label the...
The phone company calculates a customer’s monthly cell phone bill as follows: monthly service charge: $35...
The phone company calculates a customer’s monthly cell phone bill as follows: monthly service charge: $35 voice charges: First 100 minutes: $0.018 per minute Second 100 minutes: $0.034 per minute Additional minutes: $0.055 per minute a. What is the charge for a month in which 158 minutes were used? b. What is the charge for a month in which 311 minutes were used? c. Construct a piecewise function that gives the monthly charge for x minutes of usage.
Let's say that the price for a monthly cell phone plan in the US follows a...
Let's say that the price for a monthly cell phone plan in the US follows a normal distribution with a mean of $62 with a standard deviation of $18. Calculate the z-score for the cost of your cell phone plan. Then write a few complete sentences to describe: Price of my cell phone is $110 What proportion of cell phone plans are below your cost? What proportion of cell phone plans are above your cost? Is your cell phone plan...
9) According to a census that was conducted five years ago, the mean annual household salary...
9) According to a census that was conducted five years ago, the mean annual household salary in the city of Townsburg was $40,084. The mayor of Townsburg believes that there has been an economic upturn in the city since then. He appoints a team to test for evidence that the mean annual household salary in Townsburg has increased. The teams surveys a sample of 41 households. The sample has a mean annual salary of $40,862 with a standard deviation of...
Ten years ago, the mean age of death row inmates was 50.4 according to the US...
Ten years ago, the mean age of death row inmates was 50.4 according to the US Dept. of Justice. A sociologist wants to test whether that data is still accurate. He randomly selects 9 death row inmates and finds that their mean age is 34.2 with a standard deviation of 19.1. Use a 0.01 significance level to test the claim that the mean age of death row inmates is now equal to 50.4, which was the mean age ten years...
The monthly utility bills in a certain city are normally distributed with a mean of $100...
The monthly utility bills in a certain city are normally distributed with a mean of $100 and standard deviation of $12. a) A utility bill is randomly selected. Find the probability that it is: i) less than $80 ii) between $75 and $ 115 b) What percentage of the utility bills are for more than $125? c) If 300 utility bills were selected at random, how many would be less than $90? d) The utility company wants to give a...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT