Chapter 10: Statistical Inference About Means and Proportions With Two Populations
Sampling to compare the wages for unionized workers to the wages for non-unionized workers is called
independent sampling
matched sampling
none of the above
Samples of 40 regular Wal-Mart stores and 40 regular Target stores are taken in order to the average square footage of selling space are called
independent samples
matched samples
none of the above
To construct an interval estimate of the mean difference between two matched populations that are normally distributed, we use a t distribution with
n - 1 degrees of freedom
n1 + n2 degrees of freedom
n1 + n2 - 2 degrees of freedom
none of the choices are correct
The null hypothesis that states that there is no significant difference between the means of two populations can be stated as
μ1 - μ2 = 0
none of the above
When each data value in one sample is matched with a corresponding data value in the other sample, the samples are known as
corresponding samples
matched samples
independent samples
none of the above
Assume we are interested in determining whether the proportion of voters planning to vote for candidate A (pA) is significantly less than the proportion of voters planning to vote for candidate B (pB). The correct set of hypotheses for testing the above is
none of the above
We want to test whether the average life expectancy of nonsmokers (µn) is significantly more than that of smokers (µs). The correct set of hypotheses for testing the above is
none of the above
If a hypothesis is rejected at the 3% level of significance,
it must also be rejected at the 2% level of significance
it must also be rejected at the 5% level of significance
it will sometimes be rejected and sometimes not be rejected at the 5% level of significance
Not enough information is given to answer this question
e. none of the above
If two independent large samples are taken from two populations, the sampling distribution of the difference between the two sample means
can be approximated by a Poisson distribution
will havea variance of one
can be approximated by a normal distributio
will have a mean of one
none of the above
An estimator of the population proportion obtained by computing a weighted average of the point estimators obtained by two independent samples is called a pooled estimator of the population proportion.