Question:(a) 15,000 students appeared for anexamination. The mean marks were 49 andthe standard deviation of marks was 6.Assuming the marks to be normallydistributed, what proportion of studentsscored more than 55 marks?(b) If in the same examination, Grade 'A' isto be given students scoring more morethan 70 marks what proportion of thestudents will receive Grade 'A' ?

Answered: Image /qna-images/answer/4c266736-7976-44a5-9db4-ca93ef3374bf.jpg

Answered: (a) 15,000 students appeared for an…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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A manufacturer of calculator batrries claims that the mean length of life for its battry is 500 operating hours. Suppose the standard deviation of the length of life is known to be 25 operating hours,and the distribution of life length is symmetric and mound-shaped. Approxiamately what percentage of the manufacturer'sbattries will last less than 525 hours?
Let's consider the annual precipitation levels in Los Angeles county. Suppose the average annual precipitation in LA county is normally distributed with a mean of 15 inches and a standard deviation of 3 inches. We can classify the precipitation levels in the following way: Dry Annual precipitation is more than 1 standard deviation below the mean. Normal Annual precipitation is less than 1 standard deviations below the mean and less than 2 standard deviation above the mean. Humid Annual precipitation is more than 2 standard deviations above the mean. Before answering the following questions it may be helpful to mark on a bell shaped curve where the above regions lie. According to the empirical rule, what is the probability of experiencing a Dry year in Los Angeles? According to the empirical rule, what is the probability of experiencing a Humid year in Los Angeles? According to the empirical rule, what is the probability of experiencing a Normal year in Los…
Suppose that pulse rates among healthy adults are normally distributed with a mean of 79 beats/minute and a standard deviation of 8 beats/minute. What proportion of healthy adults have pulse rates that are at most 92 beats/minute? Round your answer to at least four decimal places.
According to the Empirical Rule, in a Normal Distribution of data you will have percent of the data within 1 standard deviation of the mean, percent of the data within 2 standard deviation of the mean, and percent of the data within 3 standard deviation of the mean.
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A researcher studying stress is interested in the blood pressure measurements of chief executive officers (CEOS) of major corporations. He believes that the mean systolic blood pressure, H, of CEOS of major corporations is less than 136 mm Hg, which is the value reported in a possibly outdated journal article. He plans to perform a statistical test. He measures the systolic blood pressures of a random sample of CEOs of major corporations and finds the mean of the sample to be 128 mm Hg and the standard deviation of the sample to be 16 mm Hg. Based on this information, answer the questions below. What are the null hypothesis (H) and the alternative hypothesis (H,) that should be used for the test? |Ho: H is ? |H,: µ is ? In the context of this test, what is a Type II error? A Type II error is ? fact, µ is ? v the hypothesis that u is ? when, in Suppose that the researcher decides not to reject the null hypothesis. What sort of error might he be making? ? Continue Save For Later Submit…
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