If we are testing the difference between the means of two normally distributed independent populations with samples of n1 = 10, n2 = 11, the degrees of freedom for the t statistic is ______.
19
9
8
18
If we are testing the difference between the means of two normally distributed independent populations with...
To construct an interval estimate for the difference between the means of two populations which are normally distributed and 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) degrees of freedom (n1 + n2 - 1) degrees of freedom (n1 + n2 - 2) degrees of freedom (n1 - n2 + 2) degrees of freedom
10. If we are doing two-sample hypothesis testing with related samples of sizes n1 = 10 and n2 = 10, what is the number of degrees of freedom? a. 9 b. 10 c. 19 d. 20 11. If we are doing two-sample hypothesis testing with independent samples of sizes n1 = 10 and n2 = 10, what is the number of degrees of freedom? a. 10 b. 18 c. 19 d. 20
The information below is based on independent random samples taken from two normally distributed populations having equal variances. Based on the sample information, determine the 98% confidence interval estimate for the difference between the two population means. n = 12 X1 = 57 S1 = 9 n2 = 11 X2 = 54 S2 = 8 The 98% confidence interval is $(11-12) (Round to two decimal places as needed.)
The information below is based on independent random samples taken from two normally distributed populations having equal variances. Based on the sample information, determine the 95% confidence interval estimate for the difference between the two population means. n1 14 x145 n2 13 2 47 The 95% confidence interval is s (μ1-12) s Round to two decimal places as needed)
The information below is based on independent random samples taken from two normally distributed populations having equal variances. Based on the sample information, determine the 90% confidence interval estimate for the difference between the two population means. n1 = 17 x1 44 n2 13 x2 = 49 The 90% confidence interval is s(uI-12) (Round to two decimal places as needed.) «D
The difference of two independent normally distributed random variables is also normally distributed. We have used this fact in many of our derivations. Now, consider two independent and normally distributed populations with unknown variances σ 2 X and σ 2 Y . If we get a random sample X1, X2, . . . , Xn from the first population and a random sample Y1, Y2, . . . , Yn from the second population (note that both samples are of...
13. If the populations are normally distributed and the population variances are equal but unknown, the tstatistic for testing the hypotheses about the difference between the two population means using samples of size 20 and 30 has a degree of freedom equal to ___. A. 48 B. 50 C. 19 D. 29
Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. A paint manufacturer wished to compare the drying times of two different types of paint. Independent simple random samples of 11 cans of type A and 9 cans of type B were selected and applied to similar surfaces. The drying times, in...
Independent random sampling from two normally distributed populations gives the results below. Find a 99% confidence interval estimate of the difference between the means of the two populations ni 70 X1-377 ƠI :19 n2-34 x2 334 ơ2-29 The confidence interval is < (m-μ2) (Round to four decimal places as needed)
Two 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 n 1 = 25 and n 2 = 30. The correct distribution to use is the t distribution with _____ degrees of freedom.