A random sample of 65 high school students has a normal distribution. The sample mean average ACT exam score was 21.4 with a 3.2 sample standard deviation. Construct a 90% confidence interval estimate of the population mean average ACT exam.
A random sample of 65 high school students has a normal distribution. The sample mean average...
3. A random sample of 45 students at a high school is collected and their GPA is recorded. The sample mean is computed to be 2.5 with a sample standard deviation of 1.3. i) Construct a 95% confidence interval for the mean GPA of all students at this school. For part (i), do not assume that GPA follows Normal distribution. ii) Construct an interval that is likely to include at least 90% of possible GPA values of students at this...
National average ACT score for high school students stands at 25. A teacher thinks that her students perform better than average. So she collects data for 32 students and finds out that their average is 26.5 with standard deviation 3.7. (a) Set up a hypothesis test to see whether the teacher is right (b) Construct a 95% confidence interval for the mean ACT score. Explain your choice of distribution in constructing the confidence interval (normal or t-distribution). (c) Find the...
An SRS of 380 high school seniors gained an average of ?¯=20.23 points in their second attempt at the SAT Mathematics exam. Assume that the change in score has a Normal distribution with standard deviation σ=47.28. We want to estimate the mean change in score ?μ in the population of all high school seniors. (a) Using the 68 – 95 – 99.7 Rule or the ?-table (Table A), give a 95% confidence interval (?,?) for ? based on this sample....
Steve wants to estimate the average ACT scores of students graduated from his high school. He randomly selected 30 students from an email list and ask them to provide the information. Of them 15 students replied and the summary of the ACT score is as below: Mean STD Min Max 21.6 8.4 14 32 (1) (2pts) In this study, what is the sample of the study? What is the population of the study? (2) (5pts) Steve is told that the...
The mean exam score for 44 male high school students is 20.1 and the population standard deviation is 4.7. The mean exam score for 58 female high school students is 19.6 and the population standard deviation is 4.1. At a = 0.01, can you reject the claim that male and female high school students have equal exam scores? Complete parts (a) through (e). Click here to view page 1 of the standard normal distribution table. Click here to view page...
An SRS of 500 high school seniors gained an average of x 25 points in their second attempt at the SAT Mathematics exam. Assume that the change in score has a Normal distribution with standard deviation ơ-54. (a) Find a 90% confidence interval for the mean change in score μ in the population of all high school seniors. (Enter your answers rounded to two decimal places.) lower bound of confidence interval: upper bound of confidence interval: (b) What is the...
4. You want to estimate the mean SATM score for 250,000 high school seniors in California. Only about 45% of California students take the SAT. These self-selected students are planning to attend college and are not representative of all California seniors A simple random sample (SRS) of 500 California high school seniors is tested. The mean score of the sample is Y 461. What could you say about the mean score, n-508 in the population of all 250,000 seniors? Assume...
An SRS of 380 high school seniors gained an average of....
An SRS of 380 high school seniors gained an average of -23.11 points in their second attempt at the SAT Mathematics exam. Assume that the change in score has a Normal distribution with standard deviation σ = 48.85. We want to estimate the mean change in score μ in the population of all high school seniors. (a) Using the 68-95-99.7 Rule or the z-table (Table A), give a 99.7%...
(4)Five hundred students from a local high school took a college entrance examination. Historical data from the school record show that the standard deviation of test scores is 40. A random sample of thirty- six students is taken from the entire population of 500 students. The mean test score for the sample is three hundred eighty. Find (a) 95% confidence interval for the unknown population mean test score. (b) 95% confidence interval for the unknown population mean test score if...
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132 /texttornework 2001) Draw the Distribution and mark off your ample means. Conspite the Test Statistic: Calculate the p value • Do you Reject the H or Fail to Reject the H.? • Write out a statement describing your conclustion. 2.2 Confidence Interval High school students who take the SAT mathematics exam a second time generally score higher than on their first attempt. The change in score has a Normal distribution with a standard deviation y...