1. True or False.
(a) If all the observations in a data set are identical, then the variance for this data set is zero.
(bIf A and B are disjoint, P(A) = 0.4 and P(B) = 0.5, then P(A AND B) = 0.2.
(c) The mean is always equal to the median for a normal distribution.
(d) A 95% confidence interval is wider than a 98% confidence interval of the same parameter.
(e) It’s easier to reject the null hypothesis in a hypothesis test at 0.05 significance level than at 0.01 significance level.
2. Choose the best answer. Justify for full credit.
(a) A study was conducted at a local college to analyze the average GPA of students graduated from UMUC in 2016. 100 students graduated from UMUC in 2016 were randomly selected, and the average GPA for the group is 3.5. The value 3.5 is a
i (i) statistic
ii (ii) parameter
iii (iii) cannot be determined
� (b) The hotel ratings are usually on a scale from 0 star to 5 stars. The level of this measurement is
i (i) interval
ii (ii) nominal
iii (iii) ordinal
iv (iv) ratio
(c) On the day of the Virginia Primary Election, UMUC News Club organized an exit poll at three polling stations were randomly selected and all voters were surveyed as they left those polling stations. This type of sampling is called:
i (i) cluster
ii (ii) convenience
iii (iii) systematic
iv (iv) stratified
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- Submitted On 14 Jul, 2017 04:20:49