I need some help with these hypothesis testing and standard error questions: 1. The mean of a normal probability distribution is 60; the standard deviation is 5. (a) About what percent of the observations lie between 55 and 65? (b) About what percent of the observations lie between 50 and 70? (c) About what percent of the
An experiment to compare the tension bond strength of polymer latex modified mortar (Portland cement mortar to which polymer latex emulsions have been added during mixing) to that of unmodified mortar resulted in x-bar = 18.12 kgf/cm^2 for the modified mortar (m = 40) and y-bar = 16.87 kgf/cm^2 for the unmodified mortar (n = 32)
For a t distribution with 12 degrees of freedom, find the area, or probability. Develop a 95% confidence interval estimate of the population mean cost for a prescription of Zocor. How large of a sample should be taken if the margin of error is. If we want to estimate the population mean travel to work time for New York City residents with a margin of error of 2 minutes what sample size should be used? What is the margin of error associated with a 95% confidence interval for the group of users who are women? Construct a 95% confidence interval for the group of people in the population who get their major source of news from a tv set. How large of a sample would be needed to estimate the population proportion with a margin of error of 0.05 at a 95% confidence level?
(1) For a t distribution with 12 degrees of freedom, find the area, or probability, that is in each region: (A)To the left of 1.782 (B)To the right of -1.356 (C)To the right of 2.681 (D)To the left of -1.782 (E)Between -2.179 and +2.179 (F)Between -1.356 and +1.782 (2) Due to constituents' complaints to their representa
The Bureau of Labor Statistics (BLS) uses 90% confidence in presenting unemployment results from the monthly Current Population Survey (CPS). The Jan. 2000 survey interviewed 133,357 members of the civialian labor force. Of these, 6264 were unemployed. The CPS is not a simple random sample, but for the purposes of this exercise
Develop a 99 percent confidence interval for the population mean. Construct a 95 percent confidence interval for the mean number of misspelled words in the population of student essays. Construct the 99 percent confidence interval for the population proportion. The estimate is to be within $100. How many families should be interviewed?
7. Bob Nale is the owner of Nale's Texaco GasTown. Bob would like to estimate the mean number of gallons of gasoline sold to his customers. From his records, he selects a random sample of 60 sales and finds the mean number of gallons sold is 8.60 and the standard deviation is 2.30 gallons. a. What is the point estimate of the
The average number of textbooks received per year by 100 college professors at GCU is 30 with a standard deviation of 3. What is the 99% confidence interval of the true mean?
A random sample of 16 women in a beginning aerobics class had a mean weight of 142 pounds and a standard deviation of 12 pounds. What is the 95% confidence interval of the mean weight of all women in the aerobics class?
Construct a graph determining the probability for the following problems. The sample mean and sample standard deviation are present. Construct a 90% confidence interval using the population mean and sample size.
1. Three hundred of 450 drivers surveyed indicated that they would consider bying retread tires. Find a 95% confidence interval for the true proportion of all who might buy retread tires. 2. Insurance industry analysts report that the average amount of life insurance in effect in Virginia is $92,500 with a sample standard de
1) Suppose that 64 smokers were sampled. Assume the sample mean and the sample standard deviation remained the same ($20 and $5, respectively). a. What is the 95% confidence interval estimate of u? b. A research a firm a conducted a survey to det
I am struggling with this portion of my assignment, please provide guidance. Using the attached article, provide an overview of the contents and apply the concepts to the Job Satisfaction survey. It is important to cover the concept of the techniques used to estimate sample size. See attachments.
UPDATE - Part B is the most important - if you are only able to help with that part, please do so. Refer to the Real Estate data, which reports information on homes sold in Denver, Colorado,last year. a. Let selling price be the dependent variable and size of the home the independent variable. Determine the regression e
Dr. Walker is an industrial psychologist. She is currently studying stress among executives of Internet companies. She has developed a questionnaire that she believes measures stress. A score above 80 indicates stress at a dangerous level. A random sample of 15 executives revealed the following stress level scores. 94 78
1. Compute the mean and variance of the following discrete probability distribution. x P(x ) 0 .20 1 .40 2 .30 3 .10 2. In a binomial situation n = 4 and π = .25. Determine the probabilities of the followi
The MBA department is concerned that dual degree students may be receiving lower grades than the regular MBA students. Two independent random samples have been selected. 100 observations from population 1 (dual degree students) and 100 from population 2 (MBA students). The sample means obtained are X1(bar)=83 and X2(bar)=85. It
Confidence Interval Estimation 1. Compute a 95% confidence interval for the population mean, based on the sample 1, 2, 3, 4, 5, 6, and 30. Change the number from 30 to 10 and recalculate the confidence interval. Using the results, describe the effect of an outlier or extreme value on the confidence interval. 7.285714 mean 1
1. Suppose that the mean income of all Mudville residents is $40,000 with a standard deviation of $6,000. Answer the following questions in terms of these data. a. What proportion of all possible samples of 36 Mudville residents would have a mean income of $38,000 or more? b. What is the probability of selecting a rando
Calculate a 95% confidence interval of the average number of Orlando Dining magazines sold over the last year. The average number sold per month is 11,500 and the standard deviation is 575.
Please help with the following problems. The manager of a local bank wants to estimate the average amount held in checking accounts by the customers. A random sample of 30 customers is selected, and the results indicate a sample average of $4,750 and a sample standard deviation of $1,200. a) Set a 95% confidence interval
The inspection division of the Measures Department in a public service is interested in estimating the actual amount of soft drink that is placed in 2 -liter bottles at the local bottling plant of a large nationally known soft-drink company. The bottling plant has informed the inspection division that the standard deviation for
1. The Environmental Protection Agency (EPA) fuel economy estimates for automobiles tested recently predicted a mean of 24.8 mpg with a standard deviation of 6.2 mpg for highway driving. Assume that the data is normally distributed. Using the 68-95-99.7 Rule, Determine: a. Within what interval you would expect the middle
Mr. James McWhinney, president of Daniel-James Financial Services, believes there is a relationship between the number of client contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample information. The X column indicates the number of client contacts last month, and the Y
Does marriage hinder the career progression of women to a greater degree than that of men? According to The Journal of Applied Psychology, in a random sample of 795 male managers and 223 female managers from 20 Fortune 500 corporations, 86% of the male managers and 45% of the female managers were married. -Use a 95% CI to es
ComputerWare asked 500 of its iMac purchasers what computer they owned or had owned. There were 83 new computer owners, 60 who had owned a Windows-based computer, and 357 who had owned a Macintosh. The proportion of first-time computer owners was 83/500 = 0.167. So, 0.167 is an estimate of the proportion of new computer owners.
Need help with chapter review questions attached.
Case study problem attached. --- The following are the number of chips per bag for the 42 bags of Chips Ahoy! analyzed. 1200 1219 1103 1213 1258 1325 1295 1247 1098 1185 1087 1377 1363 1121 1279 1269 1199 1244 1294 1356 1137 1545 1135 1143 1215 1402 1419 1166 1132 1514 1270 1345 1214 1154 1307 1293 1546 1228 1239 14
Pulse rate is an important measure of the fitness of a person's cardiovascular system. The mean pulse rate for all U.S. adult males is approximately 72 heart beats per minute. A random sample of 21 U.S. male adults who jog at least 15 miles per week had a mean pulse rate of 52.6 beats per minute and a standard deviation of 3.22
What value would you expect to find for the standard deviation of the sample mean? Determine the minimum number of subjects to be polled for a survey with a margin of error of six percentage points and a confidence level of 95%. How many of the 200 confidence interval estimate should you expect to actually contain the population mean M? What is the standard deviation of this distribution?
16) If the random variable z is the standard normal distribution, then z(0.2324) = 23) Determine the minimum number of subjects to be polled for a survey with a margin of error of six percentage points and a confidence level of 95% a.253 b.267 c.278 d.306 e.none of these 32)
See attached file. a. Determine the .95 confidence interval, in thousands of kilowatt-hours, for the mean of all six-room homes. b. Determine the .95 prediction interval, in thousands of kilowatt-hours, for a particular six-room home. Number of Kilowatt-Hours Number of Kilowatt-Hours Rooms (thousands) Rooms (thous
1. The owner of Britten's Egg Farm wants to estimate the mean number of eggs laid per chicken. A sample of 20 chickens shows they laid an average of 20 eggs per month with a standard deviation of 2 eggs per month. a. What is the value of the population mean? What is the best estimate of this value? b. Explain why we need to