In April 2025
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- A result is significant at the 0.01 level. Explain why it must also be significant at the 0.05 level.
- Why is it important to report the P-value or the test statistic when presenting the results of a hypothesis test?
1. A fair die is rolled eight times. Find the probability that no more than 2
sixes come up.
2. A consulting group believes that 70% of the people in a certain city are
satisfied with their health coverage. Assuming that this is true, find the probability
that from a random sample of 15 people.
a. Exactly 10 are satisfied with their health coverage?
b. At least 2 are satisfied with their health coverage?
c. What is the expected number of people out of 15 that are satisfied with their
health coverage?
3. You observe that the number of telephone calls that arrive each day on
your mobile phone over a period of a year, and note that the average is 3 per day.
Let X be the number of calls that arrive in any one day. Then what is the probability
of receiving at most 2 calls in any one day? at least 2 calls in any one day?
A machine producing hair pins produces 1 defective out of 400 on an average. If 100 hairpins are packed in each box, what is the probability that any given box of hairpins, hairpin will contain
1)No defectives
2)At least one defective
3)At most 2 defectives
In an oil exploration in Arabic sea, suppose that the probability of an oil strike is 1 in 500 drilling. What is the probability of having exactly 1 oil producing well in 800 explorations.
No. of birthday parties observed in a class is a poisson random variable with an average of 6/month. what is the probability that there will be 3 parties in a day?
Given the mean monthly expenditure of students is RM200 with RM1O standard
deviation and the mean weight of the student body is 50 kg with a standard deviation
of 8kg. Compare the two sets of data and determine which are more scattered.
A hospital switch board receives on an average 0.9 calls/minute. Find the probability that (i) no calls in a minute, (ii) 2 or more calls/minute
A random sample size of 25 taken with replacement from a population of 1000 with u=20 and o2=9
construct a sampling distribution of the sample mean of the population consisting of the numbers 2 5 8 11 and 14 considering a sample size of 2
A top graduate business school is interested in the starting salaries of their MBA graduates. A survey consisting of all the graduates from previous year was done and the results displayed in the table below:
n Mean Median Std. Dev. Std. Error MBA’s 175 11,500 8,700 *** 144
(a) Determine the value of ‘***’?
(b) Explain what is meant by Sampling Distribution of the Mean in the context of MBA graduates’ starting salaries?
(c) What type of distribution will the Sampling Distribution of the Mean for MBA graduates’ starting salaries follow? Give reasons for your answer.
(d) What are the available point estimator and estimate of the population mean starting salary?
(e) Which of these estimators in ‘Part (c)’ above is unbiased? Give reasons for your answer?
