The mean age of 25 randomly selected college seniors was found to be 23.5 years, and the standard deviation of all college seniors was 1.3 years. Which of the following is the correct symbol for 1.3 years? A. m B. s C. s D. A machine produces 3-inch nails. A sample of 10 nails was selected and the lengths determine
1) In what ways is the t distribution similar to the standard normal distribution? In what ways is the t distribution different from the standard normal distribution? How does the formula for the t test differ from the formula for the z test? 2) Choose a variable. Before collecting the data, decide what a likely average migh
Use a t-test to investigate the claim and assume that the population is normally distributed: A large university says the mean number of classroom hours per week for full-time faculty is more than 9. A random sample of the number of classroom hours for full-time faculty for one week is listed. At α = 0.05 , test the univ
A sample of 25 concession stand purchases show a mean purchase of $5.29 with a standard deviation of $3.02. However, a later showing of the same movie, a sample of 25 purchases where the mean was $5.12 with a standard deviation of $2.14. The means appear to be very close, but not the variances. At alpha = .05, is there a dif
Do students that finish exams first obtain better grades? A professor has kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of 19.6, while the last 24 papers handed in showed a mean score of 69.3 with a standard deviation of 24.9. Is this a signi
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test
A coin-operated drink machine was designed to discharge a mean of 8 ounces of coffee per cup. In a test of the machine, the discharge amounts in 20 randomly chosen cups of coffee from the machine were recorded. The sample mean and sample standard deviation were 8.08 ounces and .13 ounces, respectively. If we assume that the dis
The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using
Suppose that a one-tailed t-test is being applied to find out if the population mean is less than $212. The level of significance selected is 0.01 and 26 accounts are sampled. What is the critical value? A machine is set to fill the small size packages of M&M candies with 56 candies per bag. A sample revealed: 3 bags of 5
The data that you will be using for this exercise came from a survey of two insurance carriers. The first carrier (C1) was compared against the second competitor (C2). The insurance company management team wants to know how Carrier 1 compared to the second carrier. Data from 159 respondents are included. All of the 5 quest
You are provided with the male and female unemployment data for the 1960-2005 periods. Using these two samples, determine whether the data support the conclusion that female unemployment rate is higher than the male unemployment rate. Use 0.01 level of significance. INSTRUCTIONS 1. Go to the blackboard, assignment section a
Refer to the Baseball 2002 data, which reports information on the 30 Major League Baseball teams for the 2002 season. At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus teams in the National League?
Twenty students randomly assigned to an experimental group receive an instructional program; 30 in a control group do not. After 6 months, both groups are tested on their knowledge. The experimental group has a mean of 38 on the test (with an estimated population standard deviation of 3); teh control group has a mean of 35 (wi
The Business Administration department at a local university delivers some of its courses using online instruction. Of the two statistics courses offered, one is delivered online and the other is delivered on campus. Eighteen pairs of students are selected, who are well matched on a number of years and grades of mathematics cour
A hypothesis states a difference exists between two populations. Sometimes this is an obvious conclusion because the means will be very different. For example, if I gave math tests to boys and girls and the boys on average scored 20 points better than the girls, I know that is enough of a difference to conclude with accuracy tha
Which of the following is a test of the statistical significance of a particular regression coefficient? a. t-test b. R2 c. F-test d. Durbin-Watson test
If a regression coefficient passes the t-test, it means that a. the regression equation is valid. b. the regression coefficient is significantly different from zero. c. the regression coefficient can be used for forecasting. d. the regression coefficient should be included in the regression equation.
Please see attached file for full problem description. ? What are Type I and Type II errors? Why do you want to avoid them? ? What is effect size and what does it tell you about your findings? ? What is power of a statistical test and what factors affect it? ? When is it necessary to conduct a t test? ? What are the "
Please show work in excel for example. The Federal Government recently granted funds for a special program designed to reduce crime in high-crime areas. A study of the results of the program in eight high-crime areas of Miami, Florida, yielded the following results. Number of Crimes by Area A B C D E F G H Before 14
What is the difference between a z-test and a t-test? When estimating population mean, how would you determine the optimal sample size when the maximum error limit is known; however, population variance is unknown and your initial sample size is less than 30? Provide a numerical example.
Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test statistic and determining its value from the sample data, comparing the observed value to the cri
Compare the two-sample independent t test to the paired t test. Can you please compare and contrast this for me?
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test
The university data center has two main computers. The center wants to examine whether computer 1 is receiving tasks which require comparable processing time to those of computer 2. A random sample of processing times from computer 1 showed a mean of seconds with a standard deviation of seconds, while a random sample of proc
Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is $150,000, with a standard deviation of $40,000. A corresponding sam
Use the five-step hypothesis testing procedure to solve the following exercises. 1.) State the null hypothesis and the alternate hypothesis. 2.) What is the critical value of t? 3.) What is the computed value of t? 4.) Interpret the result. What is the p-value? 5.) What assumption needs to be made about the distribution o
It seems these days that college graduates who are employed full-time work more than 40-hour weeks. Data are available that can help us decide if this is true. A survey was recently sent to a group of adults selected at random. There were 15 respondents who were college graduates employed full-time. The mean number of hours work
The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using
In recent years, a growing array of entertainment option competes for consumer time. By 2004, cable television and radio surpassed broadcast television, recorded music, and the daily newspaper to become the two entertainment media with the greatest usage. Researchers used a sample of 15 individuals and collected data on the hour