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Hypothesis Testing

Test of hypothesis-Z statistic and p-value

A manufacturer claims that the mean lifetime, mean, of its light bulbs is 52 months. The standard deviation of these lifetimes is 7 months. Ninety bulbs are selected at random, and their mean lifetime is found to be 55 months. Can we conclude, at the 0.05 level of significance, that the mean lifetime of light bulbs made by this

Is there difference in the balance time across the practice groups?

A short study was conducted to determine if balance could be improved with practice technique. After obtaining the length of time (in minutes) a subject can balance on 1 leg on a 12 inch wooden block, subjects were randomly allocated to 4 practice groups. Each group was taught different technique to improve balance. Subjects wer

T test

To investigate the efficacy of a diet, a random sample of 16 male patients is drawn from a population of adult males using the diet. The weight of each individual in the sample is taken at the start of the diet and at a medical follow up 4 weeks later. Assuming that the population of differences in weight before versus after the

Using the Five-Step Hypothesis Testing

Use the five-step hypothesis testing procedure to solve the following exercises. 21. The management of Discount Furniture, a chain of discount furniture stores in the Northeast, designed an incentive plan for salespeople. To evaluate this innovative plan, 12 salespeople were selected at random, and their weekly incomes before

AIU - Testing of Hypothesis (Job Satisfaction)

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 s

Statistics matching question: definitions/examples of statistical terms

The mean number of college credits earned in the fall by students at City University is to be estimated by determining the mean number of credits earned in the fall semester by the 100 students enrolled in statistics 202. Data (one piece of) Data (set of) Experiment Parameter Population Sample Statistic Variable A

Hypothesis Testing - Real Life Example

Make a decision regarding the null hypothesis based on the sample information and interpret the results of the test, state whether we proved or disproved the null hypothesis and why the data proves this. A company needs to purchase company cars for their sales staff. They contacted their local Ford dealership and inquired as

Statistical Difference Formula

I am looking to design something in Microsoft Access, but not sure how to do the two statistical calculations. For example, assume there are two columns of data labeled January and February. In each of these columns are the numbers 0-4. Where 0=Blank Response, 1=Poor, 2=Fair, 3=Good, 4=Excellent I want to know if th

Hypothesis test for the difference of population means: Paired comparisons

Attached is 2 slides on powerpoint. The 1st slide is the problem and the 2nd slide is the answer format. Answer 3 is completed because it requires the use of a t test with degree of freedom that equals 11. Attached also is the excel data Please help with 1,2,4,5 and 6 only 1) eg: u=0 or u>0 etc 2) same as 1 3) answere

Hypothesis test for the population mean: Z test

See full problem description. A leasing firm claims that mean number of miles driven annually, mu, in its leased cars is less than 12480 miles. A random sample of 16 cars a leased from this firm had a mean of 11075 annual miles driven. It is known that the population standard deviation of the number of miles driven in cars fr

Five-step hypothesis test: has mean increased?

The breaking strengths of cables have a mean of 1825 lbs and a standard deviation of 65 lbs. The company claims that there is an improvement in breaking strength. To evaluate this claim, 16 cables are randomly chosen and tested -- their mean breaking strength is 1859 lbs. Can we support, at the 0.05 significance level, the cl

Hypothesis Testing in Excel

Many cities have adopted HOV High Occupancy Lanes to speed up commuter traffic to downtown business districts. Planning for Metro Transportation District has depended on a well-established average of 3.4 passengers per HOV. But a summer intern notes that because many firms are sponsoring van pools, the average number of passenge

Hypothesis Testing in Hockey Players

How tall are college hockey players? The average height has been 68.3 inches. A random sample of 14 hockey players gave a mean height of 69.1 inches. We may assume that x has a normal distribution with mu = 0.9 inch. Does this indicate that the population mean height is different from 68.3 inches? Use 5% level of significan

Can you write this as an equation?

The hypothesis is that the Southerners are less educated than the population at large. Now keep in mind that because this is a one tailed test, you can interchange the null and the alternate hypothesis. Also, null is usually given the benefit of the doubt. Thus the '=' sign goes with the null. In this case because we have to pro

Students t test for GPA score in SPSS

Time to complete complex math problems while listening to music was investigated using 16 high school students. Students were matched on their math gpa, then randomly assigned to either the Country Western music group or the Classical music group. a. Conduct the appropriate analysis to determine if there was an effect of t

P-Value of Quality Inspectors Test

Test of product quality using human inspectors can lead to serious inspection error problems. To evaluate the performance of inspectors in a new company, a quality manager had a sample of 12 novice inspectors evaluate 200 finished products. The same 200 items were evaluated by 12 experienced inspectors. The quality of each item

Specify the appropriate hypothesis for testing

2) Researchers at the University of South Alabama compared the attitudes of male college students toward their fathers with their attitudes toward their mothers. Each of a sample of 13 males was asked to complete the following statement about of their parents: My relationship with my father (mother) can best be described as: (1

Critical analysis of a research article

1. Analyze data analysis to determine whether the appropriate statistical procedure were used to analyze data. 2. Provide an explanation of the meaning of the results of each study based upon the findings from the statistical tests. Article attached -- it's about differences in health care in people before and after they

Null Hypothesis and Statistical procedures for wing to rotary wings aircraft data. Null Hypothesis, Alternative Hypothesis, Significance Level, Critical Value, P value are included in the solution.

Null Hypothesis and Statistical procedures. 1. You are in charge of the training program for pilots transitioning from fixed wing to rotary wings aircraft. You are considering the purchase of a simulator for initial training, but you are unsure if the quality of the simulator training will be worth the expenditure. You have a

Hypothesis Testing: buffered aspirin

A physician's health study of the effectiveness of aspirin in the reduction of heart attacks was begun in 1982 and completed in 1987. Of 11,037 male medical doctors in the United States who took one 325 mg buffered aspirin tablet every other day, 104 suffered heart attacks during the five-year period of the study. Of 11,034 male

Solve using the five step hypothesis testing.

The management at Black Angus is considering hiring 8 additional servers. Currently 12 servers are serving 4 tables each per hour. Servers make $11.25 on overtime per hour. Servers are having to work 2 hours of overtime per day 4 days a week. Would hiring 8 additional servers 4 days a week at $7.50 per hour working 6 hour sh

Quantitative Analysis - independent and dependent variables.

(Q: 12) Suppose you want to develop a model to predict assessed value based on heating area. A sample of 15 single-family houses is selected in a city. The assessed value (in thousands of dollars) and the heating area of the houses (in thousands of square feet) are recorded with the following results: House Assessed Valu

Explain the null and alternate hypotheses

Discuss the null hypothesis. How is it framed? What is the alternate hypothesis? How does it relate to the null hypothesis? Can you have possible outcomes not embraced by the null or alternate hypotheses?

Uric acid blood tests for males - statistics

Over a period of months an adult male patient has taken eight blood tests for uric acid. The mean concentration iswas x with a line over it =5.35 mg/dl. The distribution of uric acid for the health adult male can be assumed to be normal with the standard deviation of 1.85 mgdl. a. Find a 95% confidence interval for the popula

Stats - Sampling Distributions and Hypothesis Tests

1. The scores on a placement test given to college freshmen for the past five years are approximately normally distributed with a mean µ = 74 and a variance ơ ² = 8. Would you still consider ơ ² = 8 to be a valid value of the variance if a random sample of 20 students who take this placement test this year obtain