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Student's t-Test

T-Test

An Excel Spreadsheet is reprinted below. Interpret the t-test results. Are they statistically significant? t-Test: Paired Two Sample for Means Beer Soda Variable 1 Variable 2 Mean 16.83333333 15.8

T-Test

The managers in a company's East and West regions were rated on the basis of the company's evaluation system. A researcher wishes to conduct a t-test of means to determine if there is a difference between the East and West regions. Perform this calculation. Region Manager Rating Region Manager

Hypotheses testing for independent sample t test.

Marks) A firm is studying the production times for two production methods. The firm is satisfied with production method A and is prepared to continue using it if the mean delivery time is the same as or less than for production method B. However, if the firm finds that the mean delivery time for method B is less than that for

Probability

Please see attached problem. -------------------------------- Ralston Enterprises has assets that will have a market value in one year as shown below: Probability 1% 6% 24% 38% 24% 6% 1% Value ($ million) 70 80 90 100 110 120 130 That is, there is a 1% chance the assets will be worth $70 million, a 6% chance the assets

Test to see if the mean of the population is at least 12 ounces.

From a population of cereal boxes marked "12 ounces," a sample of 16 boxes is selected and the contents of each box weighed. The sample revealed a mean of 11.7 ounces with a standard deviation of 0.8. Test to see if the mean of the population is at least 12 ounces. Use a 0.05 level of significance. (may use traditional or p-

Pizza parlor worksheet 2 (t-test)

Deb is the owner of Deb's Pizza Palace - an establishment that prides itself on preparing healthy but delicious pizzas sold by the slice. She is currently selling pizzas in a small shop on Monroe Ave. in Corvallis, but is considering an expansion of her current business to other campuses and needs help making this decision. S

Independent sample t test

A recent study focused on the number of times men and women who live alone buy take-out dinner in a month. The information is summarized below. Statistic Men Women Sample mean 24.51 22.69 Population standard deviation 4.48 3.86 Sample size 35

Hypotheses testing

A recent article in The Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30-year rates (in percent): 4.8 5.3 6.5 4.8 6.1 5.8 6.2 5.6 At the .01 significance level, can we conclude that the 30-year mortgage rate for s

Hypotheses testing for pineapple weight

Dole Pineapple, Inc., is concerned that the 16-ounce can of sliced pineapple is being overfilled. Assume the standard deviation of the process is .03 ounces. The quality control department took a random sample of 50 cans and found that the arithmetic mean weight was 16.05 ounces. At the 5 percent level of significance, can we c

Hypotheses testing: One sample t test

A new weight-watching company, Weight Reducers International, advertises that those who join will lose, on the average, 10 pounds the first two weeks with a standard deviation of 2.8 pounds. A random sample of 50 people who joined the new weight reduction program revealed the mean loss to be 9 pounds. At the .05 level of signifi

Intro to t Test is given.

Evolutionary theories often emphasize that humans have adapted to their physical environment. One such theory hypothesizes that people should spontaneously follow a 24-hour cycle of sleeping and waking-even if they are not exposed to the usual pattern of sunlight. To test this notion, eight paid volunteers were placed (individua

Significance level independent sample t test for comparing means

Grand Strand Family Medical Center is specifically set up to treat minor medical emergencies for visitors to the Myrtle Beach area. There are two facilities, one in the Little River Area and the other in Murrells Inlet. The Quality Assurance Department wishes to compare the mean waiting time for patients at the two locations.

T test

Evolutionary theories often emphases that humans have adapted to their physical environment. One such theory hypothesizes that people should spontaneously follow a 24-hour cycle of sleeping and waking - even if they are not exposed to the usual pattern of sunlight. To test this notion, eight paid volunteers were placed (indivi

T-Test on Adaption to Physical Environment

Evolutionary theories often emphases that humans have adapted to their physical environment. One such theory hypothesizes that people should spontaneously follow a 24-hour cycle of sleeping and waking - even if they are not exposed to the usual pattern of sunlight. To test this notion, eight paid volunteers were placed (indivi

Independent sample t test for comparing means.

Consider the following results for two samples randomly taken from two populations. Sample A Sample B Sample Size 150 150 Sample Mean 412 405 Sample Std Deviation 128 54 A. At a .01 level of significance, test whether the

T test for employee absenteeism

The mean (m) number of employee absences in company X is 6 days annually, according to previous studies conducted by the Human Resources Department. Five years have passed without determining whether this mean continues to be the same. Therefore, the company's industrial psychologist selects a sample of 9 employees and deter

Introduction to a T test

Evolutionary theories often emphases that humans have adapted to their physical environment. One such theory hypothesizes that people should spontaneously follow a 24-hour cycle of sleeping and waking - even if they are not exposed to the usual pattern of sunlight. To test this notion, eight paid volunteers were placed (individu

T- Test of a Multiple Regression Model

Using 19 observations on each variable, a computer program generated the following multiple regression model: y = 43.7 - 1.83x_1 - 4.25x_2 If the standard errors of the coefficients of the independent variables are, respectively, 1.24 and 2.04, can you conclude that the independent variable is needed in the regression m

Independent sample t test

Two new york designs are under consideration for possible adoption in an assembly plant. A time study is conducted with 10 workers using design 1, and 12 workers using design 2. The means and standard deviation of their assembly times in minutes are below. Design 1 Design 2 Mean 78.3 minute

Samples of Independence Between Two

When a researcher has two samples with two means, one of the assumptions for two samples is independence of between the two samples. What does this mean? What happens if the independence assumption is violated?

Statistics - P-value Concept Approach

The Speedy Oil Change Company advertised a 15-minute wait for an oil change. A sample of 23 oil changes showed a mean time of 16.5 minutes and a standard deviation of 4.3 minutes. At the 5% level of significance, is there evidence that the mean time for an oil change is different from 15 minutes? Assume the population is approxi

T- Test for Matched Groups

1. Outline the difference between the t test for independent groups and the t test for matched groups. 2. A researcher computed the F ratio for a four-group experiment.The computed F is 4.86. The degrees of freedom are 3 for the numerator and 16 for the denominator. a. Is the computed value of f significant at p <.05? Exp

T test for mean annual income

Past records suggest that the mean annual income,m1 , of teachers in state of Connecticut is less than or equal to the mean annual income,m2 , of teachers in California. In a current study, a random sample of 25 teachers from Connecticut and an independent random sample of 25 teachers from California have been asked to report t

Which statistical test to use?

You want to compare differences in sales dollars (DV) for 43 employees before and after they have attended a motivational seminar. Since comparing differences is the goal, I presume that you are going to compare the means of a pre-post test of the 43 employees. Okay, I was going to say that this is the answer but lets be hon

A comparison of T test, Z test

Suppose that we want to estimate the mean cholesterol level in adults aged or more. We choose a random sample of such levels. The random sample we choose has a mean of mg/dL and a standard deviation of mg/dL. For each of the following sampling scenarios, determine which test statistic is appropriate to use when making inferen

T-Test for AIU job satisfaction data

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, determining the appropriate critical value, selecting the test statistic and determining its value from the sample d

T test for AIU jobsatisfaction data.

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, determining the appropriate critical value, selecting the test statistic and determining its value from the sample d

Independent Sample T Test: Example Problem

Pre-Step: Calculate the statistics from your sample. Group # 1 Group # 2 Mean Variance Standard Deviation Sample Size Step I: State the Null and Alternative Hypothesis Step 2: a. One-Tail or Two-Tail Test: ________________ b. Choose a Test Statistic: __________ c. Critical Value of the Test