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An experiment determined that taking aspirin daily reduces one's probability of suffering a heart attack. The research project, which was scheduled to last for 5 years, involved 22,000 American physicians (all male). Half took an aspirin tablet three times per week, while the other half took a placebo on the same schedule. The study was conducted in 1982, and at that time, the mean age of the physicians was 50. In the years following the experiment, the physicians were monitored for other medical conditions. One of these was the incidence of cataracts. There were 1,084 cataracts in the aspirin group and 997 in the placebo group. Do these statistics allow researchers to conclude that aspirin leads to more cataracts?
Topic: Normal Distribution Distribution & Inverse Normal Distribution
1.) The continuous random variable Z has a standard normal distribution, N (0,1). Find the following probabilities by using tables.
a.) P(Z>2)
b.) P(Z<1.35)
c.) P(-0.8<Z<1.8)
Topic: Normal Distribution Distribution & Inverse Normal Distribution
- If a student scored 82 points on a test where the mean score was 78.2 and the standard deviation was 3.7. The student's z score is _______.
A. 21.14
B. 22.16
C. 0.28
D. 1.03
Topic: Normal Distribution Distribution & Inverse Normal Distribution
1.) The value of P( -1.96 < Z < 1.96 ) is .
A. 0.9000
B. 0.9500
C. 0.9900
D. 0.9990
2.) The area under a normal curve between 0 and -1.75 is __________.
A. 0.0401
B. 0.9599
C. 0.4599
D. None of the above
A questionnaire is being devised to collect data from a sample of single South African adults to
answer the following two research questions:
A. Are single men and single women equally likely to prefer cats and dogs as pets?
B. Is there a difference between single South African men and women in how many pets
they own?
Assess each of the questions below for inclusion in the questionnaire: Should the question be
included or not? Explain your choices by discussing the necessity, relevance, clarity, and lack
of bias of each of the suggested questions. A question should only be included if it satisfies all
these criteria, and you should only include questions which are needed to answer the two research
questions. (Note that you need to assess the questions as a researcher. We are not asking you to
answer these questions yourself!)
(a) Please indicate your gender (Options: Male, Female)
A survey on economic status of seafarer showed that 70% are successful while 30% failed. A case history of 20 seafarer are now under study. What is the probability that more than 12 of them are successful? Find the mean, variance and standard deviation.
Problem. Find the probability value of P(Z< - 0.5)
Find the mean, variance, and standard deviation of the probability distribution of the random variable X, which
can take only the values 1,2 and 3, given that P(1)= 10/33, P(2)= 1/3, and P(3)= 12/33.
#339914 on Dec 2023