(d) Decide whether to reject or fail to reject the null hypothesis. O A. Fail to reject H, because the standardized test statistic is in the rejection region. O B. Reject H, because the standardized test statistic is in the rejection region. OC. Fail to reject Ho because the standardized test statistic is not in the rejection region. O D. Reject Ho because the standardized test statistic is not in the rejection region. (e) Interpret the decision in the context of the original claim. At the 5% significance level, there V enough evidence to V the claim that the mean monthly residential electricity consumption in a certain region kWh.

A study was conducted to determine the proportion of people who dream in black and white instead of color. Among 297 people over the age of 55, 75 dream in black and white, and among 310 people under the age of 25, 19 dream in black and white. Use a 0.05 significance level to test the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25. Complete parts (a) through (c) below. a. Identify the test statistic. z= 6.51 (Round to two decimal places as needed.) Identify the P-value. P-value = 3.770o (Round to three decimal places as needed.) What is the conclusion based on the hypothesis test? The P-value is greater than the significance level of a = 0.05, so fail to reject the null hypothesis. There is insufficient evidence to support the claim that the proportion of people over 55 who dream in black and white is greater than the proportion for those under 25. b. Test the claim by constructing an appropriate confidence…

A writing test is given to incoming freshman at a state university before and after they complete a required class on introductory writing. Scores are between 0 and 50 with a higher score indicating that the student has a more positive attitude toward writing. The test scores for a random sample of 15 freshman before and after they completed the introductory writing course are given below. Conduct a hypothesis test to see whether the writing class helped improve the students’ attitudes about writing. Use a significance level of 0.05.    Before 35 5 40 18 25 24 46 20 8 22 47 12 24 3 49 After 37 5 37 19 31 28 48 11 11 25 43 16 20 7 48  Hypothesis test needed

For a certain year, a study reports that the percentage of college students using credit cards was 87%. A college dean of student services feels that this is too high for her university, so she randomly selects 225 students and finds that 190 of them use credit cards. At the .01 significance level, is she correct about her university?