Explore BrainMass

Student's t-Test

An average computer mouse inspector can inspect 50 mice per hour. The 48 computer mice inspectors at a particular factory can only inspect 46 mice per hour with a standard deviation of 10. At = 0.025, does the company have reason to believe that these inspectors are slower than average?

An average computer mouse inspector can inspect 50 mice per hour. The 48 computer mice inspectors at a particular factory can only inspect 46 mice per hour with a standard deviation of 10. At = 0.025, does the company have reason to believe that these inspectors are slower than average? A doctor believes that the standard d

Independent sample t test: Team A vs. B

Use these parameters to solve and compare. Team A vs B Total of 10 A and 10 B Results of Team A: 7, 8, 5, 2, 3, 9, 6, 6, 7, 9 Team B: 2, 4, 4, 1, 2, 9, 3, 3, 5, 2 (better team) - Show formula used and walk through the steps. - State the hypotheses and identify the claim - Find the critical values - Compute the

AU Cellular: Create a hypothesis Test to compare to Softbank Cellular

AU Cellular believes their sales are more consistent than their rival Softbank Cellular. Below is the number lost calls a day over the last seven days. Do you agree with AU? Use the .01 significance level. Softbank, 78, 98, 54, 57, 68, 64, 70 AU, 75, 81, 81, 40, 82, 75, 35 - Show formua used and walk through the steps. -

T-Test for differences in groups investing in high interest savings accounts

Group Statistics   Group N Mean Std. Deviation Std. Error Mean Annual Income Control Group 42 20813.7143 10578.81613 1632.34677 Experiment Group 42 22258.7619 8896.90632 1372.82245 Independent Samples Test   Levene's Test for Equality of Variances t-test for Equality of Means F Sig. t df Sig. (2-tailed) Mean Diff

Statistics: Hypothesis test for maintenance manager of new repair method

A maintenance manager must test a new repair method that should increase the expected time between repairs. For each machine used in the study, she recorded the last time between failures prior to using the new method, which she called "Current," and the first time between failures after using the new, which she called "New." Th

ANOVA & Tukey T- test

See attached file. Interpret analysis using Tukey test on Question #5 Test Message cell D and Question # 8 Internet cell 0 with Question #8 E- mail cell P What is the correct decision process using relative to the null

t-statistics with interpretation and assumptions

Consider the filling operation for 20-oz bottles of a popular soft drink. Historically, this operation averages 20.2 oz. A recent random sample of 12 bottles yielded these volumes: 20.0 20.1 20.0 19.9 20.5 20.9 20.1 20.4 20.2 19.1 20.1 20.0 a. Find the sample mean for these data. b. Assume that the historical av

Test difference in mean battery life of two types of digital cameras

Q-5a. One of the important features of a camera is the battery life as measured by the number of shots taken until the battery needs to be recharged. The data below contain the battery life of 31 subcompact cameras and 15 compact cameras. Assuming that the population variances from both types of digital cameras are equal, is

Statistics: Union membership, Free school lunches, Automobile parts production

1. Union Membership Nationwide 13.7% of employed wage and salary workers are union members (down from 20.1% in 1983). A random sample of 300 local wage and salary workers showed that 50 belonged to a union. At ?=0.05, is there sufficient evidence to conclude that the proportion of union membership differs from 13.7%? 2. F

Hypothesis Testing and Variance using AIU data for job satisfaction

See attached file. Using AIU's survey responses from the AIU data set,complete the following requirements in the form of a report: 1. Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. 2. Begin by creating a null and an alternate statement. 3. Us

Hypothesis Test

A United Nations report shows the mean family income for Mexican migrants to the United States is $27,150 per year. A FLOC (Farm Labor Organizing Committee) evaluation of 30 Mexican family units reveals a mean to be $29,500 with a sample standard deviation of $11,150. Does this information disagree with the United Nations report

T Distribution, normal distribution, standard normal density curve

Question 6 Consider a t distribution with 26 degrees of freedom. Compute P (-1.2 < t < 1.2). Round your answer to at least three decimal places. Consider a t distribution with 19 degrees of freedom. Find the value of c such that P (t <=c) = 0.05. Round your answer to at least three decimal places. Below is a graph of a

Independent Samples T-Test

I have provided an independent T-test analysis for you on the difference between mathematics standardized scores for a small sample of students in Veracruz, Mexico given their vision as either blurry or ok. Are the average scores different? At what level of significance? Is it what you would expect? What could account for this

T-Test for Hypothesis in EXCEL

t-tests On the attached excel file are data on cancer rates by region for the whole of Scotland. The data were collected in 2000 and are expressed as rates per 100,000. If you were to compare the statistical likelihood of a man or a woman contracting lung cancer using a t-test Excel would produce the following output. t-Te

T Test for treatment of aggressive behavior

Discuss how a t test for a dependent variable can be of great value in applying a new approach to the treatment of aggressive behavior to a small group of students. Why would this t test be preferred to using another test statistic?

Quality Motors: test hypothesis for consumer group's purpose, mean average MPG

See attached Excel file. Quality Motors is an automobile dealership that regularly advertises in its local market area. It claims that a certain make and model of car averages 30 miles to a gallon of gas and mentions that this figure may vary with driving conditions. A local consumer group wishes to verify the advertising cla

Significance of the mean difference

Duplicate readings, using two separate instruments, were obtained on ten samples. What is the tabular value of the statistic used to determine the significance of the mean difference at the .05 level of probability?

Hypothesis Testing of Mean: Waiting time for Lunch

A fast food chain restaurant chain claims that lunch will be served within nine minutes of placing your order, or it is free. A sample of eight customers revealed the following waiting times in minutes: 10.1 9.3 9.2 10.2 9.3 9.6 9.4 8.8 At the .01 significance level, can we conclude that the waiting time for lunch exc

Independent samples, pooled estimate of variance

What are independent samples? What is a pooled estimate of variance and why do you need to calculate it? When do you use a dependent versus an independent sample t test? Which is the more powerful t test? What are the assumptions of the independent t test? What are the mechanics of conducting an independent samples t test?

P-Value for 0.01 Level One-tail Test

In a study by Web Criteria, it took an average of 2.1 minutes to locate information and buy products on the Delta Airlines website, compared to an average of 2.7 minutes on the British Airways site. Assume that data file XR11012 contains the times (in minutes) required during visits to the two websites. In a suitable one-tail te

Independent Sample t Test..

Pooled-Variances t-Test for (µ1 - µ2), Population Variances Unknown but Assumed Equal t-Test: Two-Sample Assuming Equal Variances Format 1 Format 2 Mean 6 8.166666667 Variance 9.777777778 11.06060606 Observations 10 12 Pooled Variance 10.48333333 Hypothesized Mean Differe

Students t test for mean are given

SEE ATTACHED FILE - Student t Distribution - Null and Alternative Hypotheses NOTE: Please use an Excel spreadsheet for response. Please do not just provide the answers but show in complete detail how you arrived at the answers, step-by-step, from the beginning to the end of the solution. (10.2)

What is the Test Value: new drug effectiveness between women and men

A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial they wish to determine whether there is a difference between the effectiveness for women and for men. At a=5, what is the test value? ................................Women..........Men

Assessing Critical Region: Computer Mouse Example

An average computer mouse inspector can inspect 50 mice per hour. The 48 computer mice inspectors at a particular factory can only insppect 46 mice per hour with a standard deviation of 10. At alpha = 0.025 does the company have reason to believe that these inspectors are slower than average? (Answer yes or no, the answer an

Difference for t test for independent means & correlated t test

What is the difference between a t test for independent means and a correlated t test? If a production manager wanted to determine whether or not the first shift was processing more widgets than the second shift, what type of statistical process would be used?

Hypothesis Testing: Two sample Z & t test

Please see attached files. "Salaries" and instruction below. Large Sample Case Select the Tools pull-down menu Choose Data Analysis When Data Analysis dialog box appears: Choose z-Test:Two Sample for Means Click Ok When the z-Test: Two Sample for Means dialog box appears: Enter B1:B115 in the Variable 1 Range box