1. If 95% and 98% confidence intervals were developed to estimate the true cost of the microwave, what differences would they have?
Answer
Standard errors
Interval widths
Z-variates
Both b and c
2. The distribution of Student’s t is
Answer
symmetrical
negatively skewed
positively skewed
a discrete probability distribution
3. The test statistic t has n – 1 degrees of freedom.
Answer
True
False
4. A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98 with a standard error of $0.10. If 90% and 95% confidence intervals are developed to estimate the true cost of a gallon of milk, what similarities would they have?
Answer
Point estimates
t-statistics
Standard errors
Both a and c