1. Suppose you have a confidence interval with a point estimate of 2.5 and a margin of error of 0.06. Now suppose the margin of error increases to 0.15. What happens to the interval and the accuracy of our estimate? A. The interval decreases and the accuracy of our estimate decreases. B. The interval decreases and the accuracy of our estimate increases. C. The interval increases and the accuracy of our estimate decreases. D. The interval increases and the accuracy of our estimate increases.

The graph illustrates the distribution of test scores taken by College Algebra students. The maximum possible score on the test was 130, while the mean score was 75 and the standard deviation was 12.  Use the "Empirical Rule", not a calculator or other technology. Do not round your answers. What is the approximate percentage of students who scored less than 51 on the test?%What is the approximate percentage of students who scored between 51 and 99 on the test?%What is the approximate percentage students who scored between 63 and 87 on the test?%What is the approximate percentage of students who scored between 75 and 87 on the test?%

Consider the accompanying data on flexural strength (MPa) for concrete beams of a certain type. 11.8 6.3 8.1 6.5 7.9 6.8 7.4 7.3 7.2 9.7 6.8 7.7 9.0 7.8 7.0 5.9 9.7 10.7 8.0 11.6 7.7 8.7 6.3 8.7 7.3 11.3 7.0 (a) Calculate a point estimate of the mean value of strength for the conceptual population of all beams manufactured in this fashion. [Hint: Ex, = 220.2.] (Round your answer to three decimal places.) MPa State which estimator you used. Os Ox O x Os/x O p (b) Calculate a point estimate of the strength value that separates the weakest 50% of all such beams from the strongest 50%. MPa State which estimator you used. Ox Os/x Os O p Ox (c) Calculate a point estimate of the population standard deviation o. [Hint: Ex² = 1868.08.] (Round your answer to three decimal places.) MPa Interpret this point estimate. O This estimate describes the bias of the data. O This estimate describes the center of the data. O This estimate describes the spread of the data. O This estimate describes the…

The graph illustrates the distribution of test scores taken by College Algebra students. The maximum possible score on the test was 130, while the mean score was 71 and the standard deviation was 13. 32 45 97 110 58 71 84 Distribution of Test Scores Q What is the approximate percentage of students who scored less than 45 on the test? What is the approximate percentage of students who scored between 71 and 84 on the test? What is the approximate percentage students who scored between 58 and 84 on the test? What is the approximate percentage of students who scored between 45 and 97 on the test?