Explore BrainMass

Hypothesis Testing


Chapter 9, Section 2 Problem 12 Interpreting Displays - Conduct the hypothesis test by using the results from the given displays. Bednets to Reduce Malaria - In a randomized controlled trial in Kenya, insecticide-treated bednets were tested as a way to reduce malaira. Among 343 infants using bednets, 15 developed malaria

Statistics Problem

See data file attached. Metropolitan Research, Inc., a consumer research organization, conducts surveys designed to evaluate a wide variety of products and services available to consumers. In one particular study, Metropolitan looked at consumer satisfaction with the performance of automobiles produced by a major Detroit manu

Article Review: Movies and the Mystery of the Missing Trade

Prepare an analysis of your selected article. Start by identifying and summarizing the hypothesis described in the article. Then explain whether the hypothesis was rejected or accepted, and what the implications of this finding are for the study. Be sure to properly cite your article. https://www.aeaweb.org/annual_mtg_papers/

Statistics: What is null hypothesis; tests, p value, conclusion

Independent simple random samples from two groups of patients used in an clinical trial yielded the following measurements on glucose levels following a new drug treatment: Group A: 54, 99, 105, 46, 70, 87, 55, 58, 139, 91, 102, 110 Group B: 93, 91, 93, 150, 80, 104, 128, 83, 88, 95,94, 97 Do these data provide sufficien

Statistics: T distribution, one and two tailed test, variance

4. Explain why t distribution tend to be flatter and more spread out than the normal distribution. 12. Last fall a sample of n = 36 freshman was selected to participate in a new four hour training program designed to improve study skills. To evaluate the effectiveness of the new program, the sample was compared with the

Statistics Ch 8-2, problems 22, 28, 46; Ch 8-3, P6, 18, 28; Ch 8-4, P12, 20

Chapter 8, Section 2 Problem 22 Finding critical values - Assume that the normal distribution applies and find the critical z values. x = 0.01; H1 is p > 0.5 Problem 28 Finding Test Statistics - Find the value of the test statistic z using Seat Belts - The claim is that more than 75% of adults always wear

When a Simulation is Better than Hypothesis Testing

a) Can you think of an example related to your work where a simulation could not be performed, (b) one where a simulation could be performed, yet a formal test would be preferred? (c) What specific (different than hiring) business decisions would a manager make using hypothesis testing?

Method of selection for faculty; evaluate new teaching tool

From the school of Allied Health, 10 faculty out of 40 are to be selected to attend a summer conference. Of the 40, 25 are women and 15 are men. Select the 10 by the most appropriate method. A new teaching tool developed by the Allied Health department is claimed to help 68% of students learn at a faster pace. State the

Test of Hypothesis: Type of error, Alpha, Mu vs u

I am wondering if mu is the same thing as u. I have two questions on a worksheet due (I have the others answered already) and I'm not finding mu in my book. 1. If Ho: u=30 and Ha: mu>30 and x=34.7 what type of error is made if real values mu=32 and x =33? 2. If Ho: u=50 and Ha: mu. 59 and sigma = 10 what is alpha if x excee

Sample t test: Report hypothetical results

Think about a real world situation or problem that could be addressed using a single-sample t test. For this situation or problem, clearly identify the independent and dependent variables you would study; generate the statistical null and alternative hypotheses; describe what information the effect size would tell you that the

Statistics: Two tailed test

Other research examining the effects of preschool childcare has found that children who spent time in day care, especially high quality daycare, perform better on math and language tests than children who stay at home with their mothers (Broberg, Wessels, Lamb, & Hwang, 1997). Typical results, for example, show that a sample of

Signifigance level

Number 8 A coffee manufacturer is interested in whether the mean daily consumption of regular-coffee drinkers is less than that of decaffeinated-coffee drinkers. Assume the population standard deviation for those drinking regular coffee is 1.20 cups per day and 1.36 cups per day for those drinking decaffeinated coffee. A rand

Summation by parts and Ditichlet's Test

Suppose {a_n} (n=1 to N) and {b_n} (n=1 to N) are two finite sequences of complex numbers. Let B_k = sum b_n (sum n=1 to k) denote the partial sum of the series sum (b_n) with the convention B_0=0. a. prove the summation by parts by formula sum (a_n b_n) (sum goes from n=M to N) = a_N B_N -a_M B_{M-1}- sum( [a_{n+1}-a_n}]B

Statistics problems: Analysis method, probability, time intervals

The following information is for Questions 2. It is an open secret that airlines overbook flights, but I have just learned recently that bookstores underbook (I might have invented this new term.) textbooks.......... To make a long story short, our UMUC designated virtual bookstore, MBS Direct, routinely, as a matter of bu

American Insurance Institute: Two- sample tests of hypothesis

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 price q

Sequences & series

File is attached, it's in french but english translation is below: 1.Find a formula general for the general term for the following sequences: Determine if they are convergent or divergent. If the sequence is convergent find its limit. 2.Let: a1=2 ��. a.Reasoning by induction show that 0<an=<2 b.show by induction for

Validity of test with difference sample sizes

2. A Wall Street Journal article suggests that age bias is becoming an even bigger problem in the corporate world. In 2001, an estimated 78% of executives believed that age bias was a serious problem. In a 2004 study by ExecuNet, 82% of the executives surveyed considered age bias a serious problem. The sample size for the 2004 s


4. For a candidate to win in a congressional district, he has to have won over half of the vote. The Republican candidate takes a poll to assess his chances in a two-candidate race. He polls 1200 potential voters and find that 621 plan to vote for the Republican candidate. Does the Republican candidate have a chance to win? Use

Test Airport baggage scanning machine claims of 580 bags per hour

The manufacturer of an airport baggage scanning machine claims it can handle an average of 580 bags per hour. At alpha (?) = .01, would a sample of 18 randomly chosen hours with a mean of 525 and a standard deviation of 45 support the manufacturer's claim? Do both by hand and with Excel. Note- Use a 0.05 level of significance

Statistics Problems: Test for mean, proportion, paired samples, independence

See attached file for clarity of the tables included. 1. ONE SAMPLE HYPOTHESIS TEST FOR MEAN: A bowler who has averaged 196 pins in the past year is asked to experiment with a ball made of a new kind of material. If he rolls 25 games with the new ball, averaging 204 pins with a standard deviation of 24.9, can one conclude

Statistics: Identify the test statistice, critical value, conclusion, p value

1. A coin mint has a specification that a particular coin has a mean weight of 2.5g. A sample of 39 coins was collected. Those coins have a mean weight of 2.49382g and a standard deviation of 0.01581g. Use a 0.05 significance level to test the claim that this sample is from a population with a weight equal to 2.5g. Do the coins