In a t-test with unknown variance, what values are used to calculate the t-statistic?Sample mean, sample standard deviation, and sample sizeSample mean, standard deviation, and sample sizeMean, sample standard deviation, and population sizeMean, standard deviation, and population size

The t test for the difference between the means of two independent populationsalways assumes that the respectivea. sample sizes are equalb. sample variances are equalc. populations are normally distributed if each sample size is less than 30d. All of the above

Which of the following statements is true for calculating the t-score for an independent two-sample t-test?A:    We use the sample means, sample sizes, and a pooled standard deviation.B:    We use the sample means, sample sizes, and the population standard deviation.C:    We use the mean difference between the samples, the standard deviation of the samples, and the average sample size.D:    We use the mean difference between the samples, the standard deviation of the differences, and the sample size.

What are the quantities needed to construct a confidence interval around a sample mean when sigma is unknown? Question 3Answera.Sample mean, sample size, σ, level of confidence (1-α)b.Sample mean, sample size, estimated standard deviation, level of confidence (1-α)c.calculated t score, sample size, estimated standard deviation, level of confidence (1-α)d.Sample mean, sample size, σ, margin of error

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 18 at a .05 level of significance t =Group of answer choices1.740-2.110-1.740-1.734

(a) A statistician randomly sampled 100 observations and found X̄ = 106 and s = 35. Calculate the t statistic and p value for testing.     H0 : μ = 100 against HA : μ > 100.Carry out the test at the 1% level of significance.(b) Repeat part (a), with s = 25.(c) Repeat part (a), with s = 15.