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Student's t-Test

Independent sample t test for insurance data

52. The president of the American Insurance Institute wants to compare the yearly costs of auto insurance offered by two leading companies. He selects a sample of 15 families, some with only a single insured driver, others with several teenage drivers, and pays each family a stipend to contact the two companies and ask for a pri

T test for population mean

2. Suppose you want to test the claim that population mean miu=3.5. Given a sample size of n=34 and a level of significance of alpha=0.01, when should you reject Ho? 3. Find the standardized test statistic t for a sample with n=15, sample mean=8.7, s=0.8, and alpha =0.05 if Ho is less than or equal to 8.4. 4. Find the sta

Data loading and descriptive statistics

EXERCISE #1: DATA LOADING & DESCRIPTIVE STATISTICS. Imagine that stimulus students are asked to indicate how likely they are to use a new breakfast-food/ toothpaste combination. The rating scale ranges from 0 (no chance of using the product) to 100 (certain to use the product). Your trustworthy but confused lab assistant han

Statistics on engineering widget

The engineer in a widget factory wants to test out a new form of raw materials. So a batch of widgets are made in the old manner as a control group and then a batch are made with the new materials as a comparison. If the average widget weight is statistically the same on both sets, the new materials will be used. The weights

Hypothesis Test: T-test

Please see attachment. I need help with the highlighted parts. Hypothesis test for the difference of population means: t test Medical researchers interested in determining the relative effectiveness of two different drug treatments on people with a chronic mental illness established two independent test groups. The first gr

Two or More Sample Hypothesis Testing : Graphs, Tables and Data Analysis

Implement raw data tables and computations, using both graphical and tabular methods of displaying data and results The US economy is in crisis brought on by the financial markets, the deep slump of the housing, high unemployment, and the slowdown of consumer spending. This has caused problems for buyers and sellers in the

Correlation and regression

Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. Assuming that the variances of the time volunteered by females and males are equal, at the .01 level of significance, is t

Question about Confidence interval and t test

Part 1 Biting an unpopped kernel of popcorn hurts! As an experiment, a self-confessed connoisseur of cheap popcorn carefully counted 773 kernels and put them in a popper. After popping, 66 unpopped kernels were counted. A. Construct a 90% confidence interval for the proportion of all kernels that would not pop. 1. What

One sample t test hypothesis test

Let's say I have 2 hypothesis. Alternate hypothesis: I will save more than 100,000 by utilizing other cost cutting measures other than layoffs. Null Hypothesis: The company will save 100,00 by the layoff of employess across the company and it's a far less risking process. Question: Can I denote my hypothesis numeric

One sample t test.

Please see the attached formulas. DQ 3.3 From Lind Chapter 10: One-sample Test of Hypothesis. Two formulas are shown below, explain the differences in then, and describe when you would use each of the formula.

Z score and T test

Z test At a retail store, customer survey is South Dallas the average household income of 75 household showed $90K with standard deviation of $25K. At another store in North Dallas, the household income of 60 households surveyed showed $120K with standard deviation of $30K. At significance level of 0.07, can a research anal

Statistics: hypothesis test with a t-statistic.

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

Independent sample t test for comparing population means

1) Survey showed 75 new employees hired at one employment place had an average salary of $60K with standard deviation of $20K. At another employment place, the average income of 60 households surveyed showed $85K with standard deviation of $25K. At significance level of 0.05, can a surveyor conclude that population means are dif

Paired T Test Example Problem

In a test of a new surgical procedure, five respected surgeons in FlatBroke Township were invited to Carver Hospital. Each surgeon was assigned two patients of the same age, gender, and overall health. One patient was operated upon in the old way, and the other in the new way. Both procedures are considered equally safe. The tim

Hypothesis testing

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers

Means and Deviation

If 15 subjects take a pre-test and a post-test with a mean change score of 1.5, and if the standard deviation of the comparison distribution is calculated to be .5, what is the t score? A. 1.5/(15-1)=0.11 B. 1.5/15=0.10 C. 1.5/.5=3.00 D. 1.5/(.5(15-1)=0.21 A school counselor claims that he has developed a technique

Two-sample hypothesis tests

One group of accounting students took a distance learning class, while another group took the same course in a traditional classroom. At £ = .10, is there a significant difference in the mean scores listed below? (a) State the hypotheses. (b) State the decision rule and sketch it. (c) Find the test statistic. (d) Make a deci

The answer to Hypothesis testing : Five step method T test

In two independent samples, from populations that are normally distributed , x1 = 35.0, s1 = 5.8, n1 = 12 and x2 = 42.5, s2 = 9.3, n2 = 14. Using the 0.05 level of significance, test Ho:u1 versus H1:u1 = u2. 2. The product development team for a notebook computer company has shown picture A to a large sample of potential bu

T Test of Hypothesis for the Mean ( standard deviation Unknown)

Want you to explain step by step i want to understand more than the answer I got... 9.57 A manufacturer of chocolate candies uses machines to package candies as they move along a filling line. Although the packages are labeled as 8 ounces, the company wants the packages to contain 8.17 ounces so that virtually none of the packa

Conduct a hypothesis test on matched pairs using a paired t-test.

10. a restaurant manager wants to compare mean daily sales between two of his restaurants located several miles apart in the same city. For a one-week period the following sales data are recorded. Sunday: restaurant 1 (1916) restaurant 2 (1771) Monday: restaurant 1(991) restaurant 2 (904) Tuesday: restaurant 1 (1112) restaura

Hypothesis testing: t-statistic and z-statistic.

2.The A.C. Nelson Company Collects Data on the TV viewing habits of Americans and publishes the information in the Nielson report on television. 20 married couples are randomly selected. Their weekly viewing times, in hours are as follows Husband: 21,56,34,30,41,35,26,38,27,30,31,30,32,15,36,20,43,4,16,21 Wife: 24,55,55,34

Hypothesis testing, z-scores, chi square, t-tests, and confidence intervals.

1. Find the Z -score and percentiles for the following calculations. Interpret your findings: a) Distribution of scores: Mean= 80 Standard Deviation=5 Scores are: X= 68, 75, 64 and 54 b) A researcher is testing a null hypothesis at the 0.05 level, would you accept or reject the null hypothesis? Z= -2.30 Z= 0.

Mean Times

For one of the tasks in a manufacturing process, the mean time for tasks completion has historically been 35.0 minutes, with a standard deviation of 2.5 minutes. Workers have recently complained that the machinery used in the task in wearing out and slowing down. In response to the complaints, plant engineers have measured the

Independent sample t test..

Rental car gasoline prices per gallon were sampled at eight major airports. Date for Hertz and National car rental companies follow (USA today April 4, 2000) Airport Hertz National Boston Logan 1.55 1.56 Chicago O'Hare 1.62 1.59 Los Angeles

One sample t test for mean..

An outbreak of food-borne sickness was attributed to Salmonella enteritidis. It determined that the source of the illness was spinach. Nine production runs are sampled from the spinach processing company the spinach to determine the level of Salmonella enteritidis. Levels in MPN/g are as follows: .793 .519 .392 .419 .5

One sample t test....

A. Based on this data can the college conclude that the students in the new program performed better than the rest of the class> A one-tailed test is used equalling .05 b. Can the college conclude that the students in the new program are significantly different from the rest of the freshman class? A two-tailed test is used

Hypothesis Testing: Weight Loss

The following table shows the results after four weeks (number of pounds lost). Drug Placebo 9 8 5 6 11 2 8 3 6 5 3 6 14 2 You want to prove that the drug is effective with α=.05. Calculate the following 1) Mean and standard deviation for each sample. 2) Since i