QBA CHP 10 (Stone)

>To construct an interval estimate for the difference between the means of two populations when the standard deviations of the two populations are unknown and it can be assumed the two populations have equal variances, we must use a t distribution with (let n1 be the size of sample 1 and n2 the size of sample 2)?

(n1 + n2 - 2) degrees of freedom

>To compute an interval estimate for the difference between the means of two populations, the t distribution?

is not restricted to small sample situations

>When each data value in one sample is matched with a corresponding data value in another sample, the samples are known as?

matched samples

>If we are interested in testing whether the proportion of items in population 1 is larger than the proportion of items in population 2, the?

alternative hypothesis should state P1 - P2 > 0

>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 normal

>When developing an interval estimate for the difference between two sample means, with sample sizes of n1 and n2?

n1 and n2 can be of different sizes,

>The sampling distribution of pbar1 - pbar2 is approximated by a?

normal distribution

>The sampling distribution of pbar1-pbar2 is approximated by a?

normal distribution

>The standard error of xbar1- xbar2 is the?

standard deviation of the sampling distribution of xbar1-xbar2

>The standard error of xbar1-xbar2 is the?

standard deviation of the sampling distribution of xbar1-xbar2

>Independent simple random samples are taken to test the difference between the means of two populations whose standard deviations are not known, but are assumed to be equal. The sample sizes are n1 = 25 and n2 = 35. The correct distribution to use is the a. t distribution with 61 degrees of freedom b. t distribution with 60 degrees of freedom c. t distribution with 59 degrees of freedom d. t distribution with 58 degrees of freedom

t distribution with 58 degrees of freedom

>Independent simple random samples are taken to test the difference between the means of two populations whose standard deviations are not known, but are assumed to be equal. The sample sizes are n1 = 25 and n2 = 35. The correct distribution to use is the?

t distribution with 58 degrees of freedom

>Independent simple random samples are taken to test the difference between the means of two populations whose variances are not known, but are assumed to be equal. The sample sizes are n1 = 32 and n2 = 40. The correct distribution to use is the?

t distribution with 70 degrees of freedom