C. lower them Doeslion 15 (1 point) NASA compares the ages of stars in two distinct clusters. A sample from the first cluster has an average age of 4.205 billion years with a standard deviation of 2755 billion years. A sample from the second cluster has an average age of 1:161 billion years with a standard deviation of 2 565 billion years. NASA samples 117 stars from the first cluster, and 189 stars from the second closter. Given that the calculated 95% CI is (2 622, 376), what is the correct interpretation of this confidence interval? A. We are 95% certain that the difference in population means is between 2 522 and 3.76 B. There is a 95% chance that the difference in sample means is between2 522 and 3.76 C. We are 95%% confident that the difference in sample means is between 2 522 and 3.76 D. We are 95% confident that the difference in populations means is between 2 522 and 3.76 Question 16 (1 point) NASA compares the ages of stars in two distinct clusters. A sample from the first cluster has an average age of 2.984 billion years with a standard deviation of 2.96 billion years. A sample from the second cluster has an average age of 2.99 billion years with a standard deviation of 2.093 billion years. NASA samples 143 stars from the first cluster, and 102 stars from the second cluster. Given that the 95% CI from a point estimate of the sample mean of cluster 1 minus the sample mena of cluster two is (-0-639, 0.627), we may conclude that the population mean of cluster 1 is _. the population mean of cluster 2. A. not significantly different to B. Can't determine. C. greater than Question 17 (1 point) The CDC collects biometric data on the US population. Two weight measurements (12 months apart) are taken on a sample of 37 US citizens. The average difference of weights in the sample is-1 Ibs and its standard Heviation is 5 lbs. A confidence interval is calculated as (-2.611, 0.611). What is the correct interpretation for this confidence interval? A) There is a 95% chance that the sample average difference between the two dependent groups is between -2 611 and 0.611 B) We are 95% certain that the sample average difference in the two dependent groups is between -2.611 and 0.611 () We are 95% confident that the population average difference in the two dependent groups is between -2.611 and 0.611 D) The population average difference is 0 611 --2 611 =3.222 Question 18 (1 point) The CDC collects biometric data on the US population. Two weight measurements (12 months apart ) are taken on a sample of 23 US citizens. The average difference of weights in the sample is-8 lbs and its standard deviation is 4 1bs. A confidence interval with a point estimate of (after-before) is calculated as (-9.635, -6.365). Based on the CI, what conclusion are we able to make? A) The population average weight has decreased over 12 months B) The two weight measurements are independent. C) The population average difference in weight is not significant. Question 19 (1 point) Which of the following statements is true