correct answers
The students in a class are given an exam with a maximum score of 100. Their
numerical scores are an example of what type of data?
80 55 60 80 75 100 60 55 80 70 95 90 - ANSWER-Ans: Ratio
(since a the score is given we know it is not nominal, it is not in order so it is not ordinal
nor is it written in interval form)
These exam scores are an example of ratio data because there is a meaningful zero
point for these data, and because the ratio of two scores is meaningful. That is, a score
of zero on the exam would mean that no questions were answered correctly, and a
score of 90 on the exam would be 50% better than a score of 60.
What is the mode of the values in the table?
80 55 60 80 75 100 60 55 80 70 95 90 - ANSWER-Ans: 80
The mode is 80 because it is the most frequently-occurring value in the table.
Which situation involves two statistically independent events? - ANSWER-Ans: fair dice
thrown at the same time
How many different combinations of 2 students can be chosen from a class of 25,
where the order of selection does not matter? - ANSWER-Using the combination
formula,
n!/r!(n-r)!
A researcher performs a two-tailed test of the hypothesis that a sample mean is greater
than zero at the 90% confidence level. The population variance is known. What is the
critical value of the z-statistic? - ANSWER-1.65