A telephone company claims that private customers pay on average $17.10 per month for long-distance phone calls. A random sample of 35 customers' bills during a given month produced a sample mean of $22.10 spent on long-distance calls, and a sample standard deviation of $6.71. a. Calculate a 95% confidence interval for the average monthly long-distance phone bill.

Question

A telephone company claims that private customers pay on average $17.10 per month for long-distance phone calls. A random sample of 35 customers' bills during a given month produced a sample mean of $22.10 spent on long-distance calls, and a sample standard deviation of $6.71.

a. Calculate a 95% confidence interval for the average monthly long-distance phone bill.

Expert Answer

Want to see the step-by-step answer?

Check out a sample Q&A here.

Want to see this answer and more?

Experts are waiting 24/7 to provide step-by-step solutions in as fast as 30 minutes!*

*Response times may vary by subject and question complexity. Median response time is 34 minutes for paid subscribers and may be longer for promotional offers.
Tagged in
Math
Statistics

Hypothesis Testing

Related Statistics Q&A

Find answers to questions asked by students like you.

Q: In 2008, the Detroit Lions set an NFL record by losing all 16 regular season games. Suppose that the...

A: It is given that n =16.Here, probability of winning an individual game is 0.10.

Q: novel pages-  a random sample of 25 novels has a standard deviation of 9 pages. Find the 95% confide...

A: The sample standard deviation is 9.The sample size is 25.

Q: 3. A medical researcher examined the number of asthma attacks patients had both before and while usi...

A: Hey there! Thank you for posting the question. Since your question has more than 3 parts, we are sol...

Q: Part D and E

A: In order to get the test statistic value, the MINITAB output for the paired t-test is given below.

Q: Please See picture

A: 4.22 a) The expected number of games that are played when i=2 is -2p2+2p+2. From the given informati...

Q: Question 1

A: Let mu1 be the sample mean of acute schizophrenics and mu2 be the mean of chronic schizophrenics.Hyp...

Q: Exercise 5.7.4 A UMass Boston student has earned 55 credits toward his degree but has a GPA of just ...

A: It is given that the GPA for 55 credits is 1.8.The minimum GPA to obtain is 2.Let G be the required ...

Q: Given a population where p = 0.10, find the standard deviation of the samping distribution when n = ...

A: Click to see the answer

Q: Suppose that Felisha is a librarian, and she read in a scholarly journal that the number of words in...

A: It is given that the standard deviation is 102.0, sample size is 20 and the level of confidence is 0...

Q: A hypertension trial is mounted and 12 participants are randomly assigned to receive either a new tr...

A: 1.Hypotheses for the test is given below:

Q: From a sample with n=32, the mean number of televisions per household is 4 with a standard deviation...

A: Chebyshev’s rule can be used for the large set data. It says that at least 1-1/k2 percentage of the ...

Q: Figure 1 shows sample proportions from samples of size n=40 from a population. Estimate the value of...

A: It is given that sample size (n) is 40.The given graph shows that the sampling distribution of propo...

Q: Statistics Question

A: Hypotheses:Denote μ1, μ2 as the true average number of days spent in the hospital for childbirth, by...

Q: rosoft Edge atic/nb/ui/evo/index.html?deploymentid-589573205424674386703380718elSBN-9780357035108&id...

A: Given Datadfbetween = 2dfwithin = 30Degrees of freedom of treatments is given byK-1 = 2K represents ...

Q: Find k such that P(-k < Z < k) = .6970  it might help to sketch the situation

A: To value of k can be determine as:By using Z-table,

Q: 2. Determine Var(Y) when Y 3X1 +2X2 with Var(X1) 1, Var(X2) 5, Cov(X, X2) 2, E X1} 3, аnd E{X} 4.

A: Click to see the answer

Q: Billiard tables have mean degree of balance 0 and standard deviation 1 What is the probability ...

A: It is given that the degree of balance is normally distributed with mean 0 and standard deviation is...

Q: In the United States, the mean age of men when they marry for the first time follows the normal dist...

A: It is given that the mean and standard deviation are 29 years and 2.5 years, respectively. The sampl...

Q: The results of a common standardized test used in psychology research is designed so that the popula...

A: It is given that the mean and standard deviation are 145 and 30.

Q: Suppose that the duration of a particular type of criminal trial is known to be normally distributed...

A: a)It is given that criminal trial is known to be normally distributed with a mean of 20 days and a s...

Q: Jobs and productivity! How do banks rate? One way to answer this question is to examine annual profi...

A: The provided information is:Assume that X is defined as annual profit per employee for representativ...

Q: i need help with how to figure out this problem. i don't understand how to find the solution in a ga...

A: From the provided information, if a coin is tossed and a die is rolled than the total sample space c...

Q: Part A. Please show ti 84 steps

A: (a) The random sample, n is 60, the standard deviation is 20 and the sample mean is 32. The confiden...

Q: Billiard tables have mean degree of balance 0 and standard deviation 1. What is the probability...

A: It is given that the mean and standard deviation are 0 and 1.

Q: The average cholesterol content of a certain brand of eggs is 210 milligrams, and the standard devia...

A: Hey, since the question is not specified correctly. Here we are finding the probability that mean ch...

Q: Please show TI 84 steps

A: Note:Hey, since there are multiple sub-parts question posted, we will answer first three sub-parts. ...

Q: Please show TI 84 steps. Part d

A: a)t>2.718, df = 11=0.01( From Excel =T.DIST.RT(2.718,11))type error = significance level = 0.01re...

Q: 3. A medical researcher examined the number of asthma attacks patients had both before and while usi...

A: Hello there! there are more than three subparts in the question. According to our policies we cannot...

Q: a committe of 4 is to be selected from 6 men and 5 women. 1 particular man and 1 particular woman re...

A: From the given information, there are 6 men and 5 women. That is, the total number of persons is 11(...

Q: In jumbled box of pens and pencils, the probability of randomly choosing a sharpened pencil is .54 a...

A: Given dataprobability of randomly choosing a sharpened pencil P(S) = 0.54probability of randomly cho...

Q: Problem 1: If X1, X2, ... , Xn are a random sample from a population with mean u and variance o2, us...

A: Introduction:The method of moments estimator equates the population moments with the corresponding s...

Q: A card is selected at random in a standard deck of 52 cards. What is the probability of selecting a ...

A: The number of cards in a deck is 52. In these 52 cards number of red cards is 26 and number of black...

Q: Please show TI 84 steps

A: It is given that mean is 10, level of significance is 0.05 and the sample size is 14.From the altern...

Q: I need help on this question. Toby's Trucking Company determined that on an annual basis, the distan...

A: Hey there! Thank you for posting the question. Since your question has more than 3 parts, we are sol...

Q: A facilities manager at a university reads in a research report that the mean amount of time spent i...

A: Since, we only answer up to 3 sub-parts, we'll answer the first 3. Please resumbit the question and ...

Q: The patient recovery time from a particular surgical procedure is normally distributed with a mean o...

A: The provided information is:

Q: Toby's Trucking Company determined that on an annual basis, the distance traveled per truck is norma...

A: It is given that the mean and standard deviation are 50,000 and 12,000.

Q: A manufacturer of a chocolate candies uses machines to package candies as they move along a filing l...

A: It is given that sample mean and standard deviation are 8.159 and 0.051, respectively.The test hypot...

Q: Please show TI 84 steps

A: From the given information, the alternative hypothesis is µ<6. That is, the given test is left ta...

Q: a study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. a ...

A: It is given that confidence level is 0.95, standard deviation is 150 and margin of error E is 20.

Q: Assume the random variable X has a binomial distribution with the given probability of obtaining a s...

A: Given Datan = 9p = 0.5Required probability is given by

Q: 72% of owned dogs in the United States are spayed or neutered. Round your answers to four decimal pl...

A: Hello! As you have posted 4 sub parts, we are answering the first 3 sub-parts.  In case you require ...

Q: The lengths of pregnancies are normally distributed with a mean of 266 days and a standard deviation...

A: Click to see the answer

Q: 3. Suppose you have the following estimated equation, alcohol = 2-1.4 log price where alcohol refers...

A: The given estimate equation is shown below.

Q: A small pilot study was conducted to compare cholesterol levels in individuals before and after a lo...

A: Preliminary calculation:Using the EXCEL formula “=NORM.S.INV(1– (0.05/2))”, the z-value for 95% conf...

Q: Hypothesis Testing

A: Hypothesis Testing: The statistical hypothesis is a statement made by the researcher on the basis of...

Q: Use the sample data and confidence level given below to complete parts​ (a) through​ (d).   A drug i...

A: GivenThe total number of patients treated with drug = 4122number of patients developed adverse react...

Q: The lengths of pregnancies in a small rural village are normally distributed with a mean of 263 days...

A: Let us define the random variable X as the lengths of pregnancies in a small rural village are norma...

Q: Please see picture

A: It is provided that X defined as random variable, follow the distribution of Benford’s Law.a)To show...

Q: When I'm trying to infer the population mean from a small sample, why do I have to rely on the t-sta...

A: The assumptions for the z-statics is appropriate as given below:The samples are randomly selected fr...