Doing basic statistics for test

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Doing basic statistics for test

1. When rolling a die, the probability of getting a 4 is ____. (Points : 2)

       .25

       1.67

       .167

       none of the above

Question 2.2. The formula for the probability that two events can occur at the same time is ____. (Points : 2)

       P(AB)

       P(A+B)

       P(A) + P(B)

       this can never happen because two events are always mutually exclusive

Question 3.3. A jar contains 10 red marbles and 20 blue marbles. What is the probability of randomly selecting a red marble? (Points : 2)

       0.5

       0.33

       0.10

       0.033

Question 4.4. A random sample requires that (Points : 2)

       every individual has a chance of being selected

       the probabilities cannot change during a series of selections

       there must be sampling with replacement

       all of the above

Question 5.5. A random sample requires that (Points : 2)

       every individual has an equal chance of being selected

       individuals are selected from a convenience group

       no one knows how many people are in the population

       both a and b are correct

Question 6.6. A standard normal distribution is ____. (Points : 2)

       the standard by which all other distributions are compared

       a normal distribution with a mean of zero and the standard deviation of one

       a hypothetical distribution that does not really exist

       much larger than a regular normal distribution

Question 7.7. Sampling error occurs when ____. (Points : 2)

       samples are not identical to the population from which they came

       the researcher uses too large of a group

       the population is too large

       none of the above are correct

Question 8.8. For the past 20 years, the high temperature on April 15 has averaged 62° with a standard deviation of 12. Last year the high temperature was 68°. Based on this information, which of the following best describes last year’s temperature on April 15? (Points : 2)

       a little above average

       far above average

       above average, but it is impossible to describe how much above average

       there is not enough information to compare last year with the average

Question 9.9. A Type I Error is ____. (Points : 2)

       often the correct decision

       made when two people interpret the same data

       when a true null hypothesis is rejected

       an indication that a calculation error was made

Question 10.10. The shape of the normal distribution ____. (Points : 2)

       depends on the size of the distribution

       is “bell shaped”

       is always higher on the right side than the left

       is asymmetrical