(a) In a poll of 45 students from Statistics I class (Cohort 7; A&B), 60.5% answered “Agree” to the statement, “Statistics will be useful and relevant in my chosen career”. The lecturer wants to use this result to conduct the hypothesis testing that more than 50% of the students from Statistics I classes at Foundation Course answered “Agree”. Case I: The lecturer can test the hypothesis since the data is collected from the Foundation Course implying that Cohort 7(A&B) is the sample and Foundation Course is the population. Case II: The lecturer is wrong and the hypothesis testing result would not be reliable since the random sampling is not used in the data collection process. Choose the correct answer. A. Case I is true. B. Case II is true. C. Both of them are true. D. None of them is true. Answer: (b) First: The area to the right of z = -1.55. Second: The area to the right of z = 1.55, which of the following is true? A. The first area is bigger B. The second area is bigger C. The two areas are equal D. None of the above Answer: (c) If the mean of a normal distribution is zero, which of the followings is (are) false? I. The standard deviation must be zero. II. The variance must also be zero. III. A mistake has been made in the computations, because the mean of a normal distribution cannot be zero. A. I and II only B. II and III only C. I and III only D. All of them Answer: (d) The P(2.5 < z < 2) equals when z is a standard normal random variable, ……………. A. 0.9710 B. 0.5 C. 0.0166 D. 0.4938 Answer: (e) From a group of 45 students, we want to select a random sample of 5 students to serve on a university committee. How many combinations of random samples of 5 students can be selected? A. 225 B. 9 C. 50 D. 1221759 Answer:
(a) In a poll of 45 students from Statistics I class (Cohort 7; A&B), 60.5% answered “Agree” to the
statement, “Statistics will be useful and relevant in my chosen career”. The lecturer wants to use
this result to conduct the hypothesis testing that more than 50% of the students from Statistics I
classes at Foundation Course answered “Agree”.
Case I: The lecturer can test the hypothesis since the data is collected from the Foundation
Course implying that Cohort 7(A&B) is the sample and Foundation Course is the population.
Case II: The lecturer is wrong and the hypothesis testing result would not be reliable since the
random sampling is not used in the data collection process.
Choose the correct answer.
A. Case I is true.
B. Case II is true.
C. Both of them are true.
D. None of them is true.
Answer:
(b) First: The area to the right of z = -1.55. Second: The area to the right of z = 1.55, which of the
following is true?
A. The first area is bigger
B. The second area is bigger
C. The two areas are equal
D. None of the above
Answer:
(c) If the mean of a
I. The standard deviation must be zero.
II. The variance must also be zero.
III. A mistake has been made in the computations, because the mean of a normal distribution cannot
be zero.
A. I and II only
B. II and III only
C. I and III only
D. All of them
Answer:
(d) The P(2.5 < z < 2) equals when z is a standard normal random variable, …………….
A. 0.9710
B. 0.5
C. 0.0166
D. 0.4938
Answer:
(e) From a group of 45 students, we want to select a random sample of 5 students to serve on a
university committee. How many combinations of random samples of 5 students can be
selected?
A. 225
B. 9
C. 50
D. 1221759
Answer:
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