Time left 0:59:16 A scientist wishes to estimate the average depth of a river. He wants to be 99% confident that the estimate is accurate within 2.15 cm. From a previous study, the standard deviation of the depths measured was 4.38 cm. The sample size the scientist needs is at least: a) 25 b) 26 c) 27 d) 28 e) 24 dle/mod/quiz/attempt.php?attempt=336570&cmid=278909 Time left 0:5 A random sample of 8 observations was taken from a normal population. The sample mean is 70 and the sample standard deviation is 20. When testing at 5% significance level Hu = 80 H: 80 , we have: a) The test statistic is t=-1.41 and we don't reject H, VS. b)The test statistic is z=-1.41 and we reject H, c) The test statistic is z=1.41 and we don't reject H. d) The test statistic is t = -1.41 and we reject II, e) The test statistic is = -1.41 and we don't reject H | AL CHEMISTRY / Time left An atom of which of the following elements has the smallest first ionization energy? O a. S O b. Te Sc. O d. Se e. Po Clear my choice Nex Time left 0:59:16 A scientist wishes to estimate the average depth of a river. He wants to be 99% confident that the estimate is accurate within 2.15 cm. From a previous study, the standard deviation of the depths measured was 4.38 cm. The sample size the scientist needs is at least: a) 25 b) 26 c) 27 d) 28 e) 24 dle/mod/quiz/attempt.php?attempt=336570&cmid=278909 Time left 0:5 A random sample of 8 observations was taken from a normal population. The sample mean is 70 and the sample standard deviation is 20. When testing at 5% significance level Hu = 80 H: 80 , we have: a) The test statistic is t=-1.41 and we don't reject H, VS. b)The test statistic is z=-1.41 and we reject H, c) The test statistic is z=1.41 and we don't reject H. d) The test statistic is t = -1.41 and we reject II, e) The test statistic is = -1.41 and we don't reject H | AL CHEMISTRY / Time left An atom of which of the following elements has the smallest first ionization energy? O a. S O b. Te Sc. O d. Se e. Po Clear my choice Nex