A teacher wants to compare scores on a geology exam for two classes. The difference between the sample means is 21.4. If the standard deviation of the distribution of the difference between sample means is 16.66, and she is testing the hypothesis at the 68% confidence level, which statement is true?
A. The difference between the two means is significant, so the null hypothesis must be accepted.
B. The difference between the two means is not significant, so the alternative hypothesis must be rejected.
C. The difference between the two means is not significant, so the null hypothesis must be rejected.
D. The difference between the two means is not significant, so the alternative hypothesis must be accepted.
E. The difference between the two means is significant, so the alternative hypothesis must be accepted.
A teacher wants to compare scores on a geology exam for two classes. The difference between...
A proposed null hypothesis states that there is no difference between the mean weights of the population of two neighboring districts. The sample mean difference is 12 kilograms, and the standard deviation of the distribution of the difference between sample means is 9 kilograms.Which statement is true? A. The null hypothesis must be accepted if we choose the 68% confidence level. B. The null hypothesis must be accepted if we choose the 95% confidence level. C. The null hypothesis must...
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A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. Final examination scores from a random sample of students enrolled today and from a random sample of students enrolled five years ago were selected. You are given the following information. Today 82 Five Years Ago 88 62 112.5 54 n 45 36 What conclusion can be reached about the difference in the...
Educator wants to know if there is a differencee between summer/fall classes. Two samples of 60 students each, what would the null and alternative hypothesis be to see if there is a difference in the means of both student samples (summer/fall).??
Astatistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information Today Five Years Ago Average Score 88 112.5 36 82 What is the conclusion that can be reached about the difference in the average final examination two classes? (Use a .05 level...
A 90% confidence interval for the difference between the means of two independent populations with unknown population standard deviations is found to be (-0.2, 5.4). Which of the following statements is/are correct? CHECK ALL THAT APPLY. A. The null hypothesis that the two population means are equal is not rejected at the 10% significance level using a two-sided paired tt-test. B. The null hypothesis that the two population means are equal is rejected at the 10% significance level using a...
In order to compare the means of two populations, independent random samples of 400 observations are selected from each population, with the results found in the table to the right. Complete parts a through e below. Sample 1 overbar x = 5,305 s1= 154 Sample 2 overbar x = 5,266 s2 = 199 a. Use a 95% confidence interval to estimate the difference between the population means (mu 1 - mu 2). Interpret the confidence interval. The confidence interval is...
A 90% confidence interval for the difference between the means of two independent populations with unknown population standard deviations is found to be (-0.2, 5.4). Which of the following statements is/are correct? CHECK ALL THAT APPLY. A. A two-sided two-sample t-test testing for a difference between the two population means is not rejected at the 10% significance level. B. The standard error of the difference between the two observed sample means is 2.6. C. A two-sided paired t-test testing for...
(1 point) A 90% confidence interval for the difference between the means of two independent populations with unknown population standard deviations is found to be (-0.2, 5.4). Which of the following statements is/are correct? CHECK ALL THAT APPLY. A. The standard error of the difference between the two observed sample means is 2.6. B. A two-sided two-sample t-test testing for a difference between the two population means is rejected at the 10% significance level. C. A two-sided two-sample t-test testing...
A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today and those enrolled five years ago. A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information. Today (Population 1) Five Years Ago (Population 2) Sample Mean 83 88 Sample Variance 112.5 54 Sample Size 45 36 The 92.50% confidence interval for the difference between the...
10) (a) In a hypothesis testing procedure explain the difference between a type 1 and type 2 error (b) Explain the difference between a point estimate and an interval estimate? What is a confidence interval? (c) A poll service indicates that 74% of the public is opposed to a certain piece of legislation but there is a 95% margin of sampling error of 3.1%. Express these findings as a confidence interval. (d) You read in the paper that in a...