It is widely accepted that the overall population has a mean I.Q. score of 100 with...

It is widely accepted that the overall population has a mean I.Q. score of 100 with a standard deviation of 15 that is normally distributed. A researcher wants to find out if incoming college freshman that have identified as being math majors have a higher I.Q. than the overall population. The scores below are a random sample of the I.Q. scores for incoming freshman that have identified as math majors. Use this sample to test the claim that incoming freshman who identify as math majors have a mean I.Q. score greater than 100 using α = 0.05. 105 111 98 108 101 95 115 121 92 88 117 111 108 103 92

Expert Solution

orchestra answered 2 years ago

A population distribution of score has a mean = 100 and a standard deviation of 10....

A population distribution of score has a mean = 100 and a standard deviation of 10. Researchers plan to take a sample size of N=25. Based on the central limit theorem, 68.26% of all possible means are between the sample means of ______ A) 90 and 100 B) 95 and 100 C) 98 and 102 D) 97 and 103

Suppose that for years the mean of population 1 has been accepted as the same as...

Suppose that for years the mean of population 1 has been accepted as the same as the mean of population 2, but that now population 1 is believed to have a greater mean than population 2. Letting α = 0.05 and assuming the populations have equal variances and x is approximately normally distributed, use the following data to test this belief. Sample 1: 43.6, 45.2, 43.4, 49.1, 45.2, 45.6, 40.8, 46.5, 48.3, 45.6 Sample 2: 40.1, 36.0, 42.2, 42.3,...

A population of N = 15 scores has a mean of μ = 8. One score...

A population of N = 15 scores has a mean of μ = 8. One score in the population is changed from X = 20 to X = 5. What is the value for the new population mean? A sample of n = 9 scores has a mean of M = 20. One of the scores is changed and the new mean is found to be M = 22. If the changed score was originally X = 7, what is...

A retired statistics professor has recorded results for decades. The mean score for the population of...

A retired statistics professor has recorded results for decades. The mean score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 . Assume...

IQ scores are standardized such that the population of scores has a mean of 100 and...

IQ scores are standardized such that the population of scores has a mean of 100 and a variance of 225. Assuming IQ scores have a normal distribution, what proportion of scores will fall below 80? What proportion will fall below 75? What values occur in the top 9% of the distribution? What values occur in the bottom 9% of the distribution?

A random sample of 100 medical school applicants at a university has a mean total score...

A random sample of 100 medical school applicants at a university has a mean total score of 498 on the MCAT. According to a report, the mean total score for the school’s applicants is more than 500. Assume the population standard deviation is 6.2. At alpha equals 0.01, is there enough evidence to reject the report’s claim? 6.) Identify the null hypothesis, H naught. 7.) Identify the alternative hypothesis, H sub a. 8.) Find the standardized test statistic, z....

A sample of 100 items has a population standard deviation of 5.1 and a mean of...

A sample of 100 items has a population standard deviation of 5.1 and a mean of 21.6. Construct a 95 percent confidence interval for ?.

. Consumer Reports provided extensive testing and ratings for more than 100 HDTVs. An overall score,...

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The country of Manhattan has an overall population of 5000. The population includes 500 people who are under the age of 16, 100 who are institutionalized

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Estimating Mean SAT Math Score The SAT is the most widely used college admission exam. (Most...

Estimating Mean SAT Math Score The SAT is the most widely used college admission exam. (Most community colleges do not require students to take this exam.) The mean SAT math score varies by state and by year, so the value of µ depends on the state and the year. But let’s assume that the shape and spread of the distribution of individual SAT math scores in each state is the same each year. More specifically, assume that individual SAT math...

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