The t distribution should be used whenever ___________________________________________________________________________________.

A sample statistic, such as , that estimates the value of the corresponding population parameter is known as a ______________.

The tests of significance in regression analysis are based on assumptions about the error term ɛ. One such assumption is that the values of ɛ are: ______________________.

The symbol σ2 is used to represent the ____________________________________________________________.

The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of its tires has increased. In order to test the validity of this belief, the correct set of hypotheses is ____________________________________________.

Examine the scatter diagram. ch.14 quiz01.png What observation can be considered as an outlier?

In tests about a population proportion, p0 represents the _______________________________________________.

When constructing a confidence or a prediction interval to quantify the relationship between two quantitative variables, what distribution do confidence and prediction intervals follow?

The z value for a 97.8% confidence interval estimation is __________. z dsistribution table from 0.0 to 2.49.jpg

Exhibit 2-1The numbers of hours worked (per week) by 400 statistics students are shown below. Number of hoursFrequency   0 −  9  20 10 − 19  80 20 − 29200 30 − 39100Refer to Exhibit 2-1. The relative frequency of students working 9 hours or less ______________.