Please help me clarify. Find a confidence interval for the mean/difference of the means of the entire population assuming that the population variance/s is/are unknown.

34 28 What is the value of the pooled standard deviation? *, Suppose the following data are selected randomly from a population of normally distributed (1 Point) values. Find a 98% confidence interval for the difference in the population means. Assume that the population variances are equal and unknown. (Read the problem carefully. Refer to items 29-37 for the questions regarding this problem.) 2.8145 3.7249 Population 1 Population 2 2.9945 (n = 4 (n = 5) 3.1521 10 12 16 15 12 10 19 15 13 35 What is the value of the lower confidence limit (LCL)? * 29 (1 Point) What is the sample mean of the first population? * (1 Point) -6.21 -8.04 12.11 -6.57 13.25 O -6.89 13.64 14.01 30 36 What is the sample mean of the second population? * (1 Point) What is the value of the upper confidence limit (UCL)? * (1 Point) 13.80 O 12.11 O 5.11 13.27 O 14.64 O 6.94 5.47 31 5.79 What is the sample standard deviation of the first population? * (1 Point) O 2.7538 2.3152 37 2.4215 Interpretation * None of the choices above (1 Point) 32 What is the sample standard deviation of the second population? * The researcher is 98% confident that the difference between the two population means with equal and unknown (1 Point) population variances is between -6.21 and 5.11. 3.2405 The researcher is 98% confident that the difference between the two population means with equal and unknown 3.0541 population variances is between -8.04 and 6.94. 3.1403 The researcher is 98% confident that the difference between the two population means with equal and unknown None of the choices above population variances is between -6.57 and 5.47. The researcher is 98% confident that the difference between the two population means with equal and unknown 33 population variances is between -6.89 and 5.79. What is the t-critical value? * (1 Point) 3.143 2.998 O 2.896 2.821