A random sample of 115 students has a test score average of 78 with a standard deviation of 10.3. Find the margin of error if the confidence level is 0.99. (Round answer to two decimal places)
A random sample of 115 students has a test score average of 78 with a standard...
A random sample of 225 exams score drawn from a large population of students has a mean of 60 and a sample standard deviation of 9. Estimate the population mean with a confidence level of 95%. _______< mean<________ Estimate the population mean with a confidence level of 98%. _______ <mean <________ Your final answers should be correct to 4 places after the decimal point. For a confidence level of 95% assuming the same statistics find the sample size that would...
A sample of 36 randomly selected students has a mean test score of 83.4 with a standard deviation of 8.92. Assume the population has a normal distribution. Find the margin of error, and then find the 95% confidence interval for the population mean.
you extract a sample of 115 students from this university. The sample proportion is the proportion of students in this sample who live on campus. The standard deviation of the sampling distribution of this sample proportion, rounded to four decimal places, is: 5. A random sample of 82 customers, who visited a department store, spent an average of $71 at this store. Suppose the standard deviation ofexpenditures at this store is σ. $19. The 98% confidence interval for the population...
A random sample of 50 student test scores produced an average of 85 with a standard deviation of 15. Using Excel, what is the t value for a 95% confidence interval for the mean score? Round your answer to three decimal places.
A random sample of 78 eighth grade students' scores on a national mathematics assessment test has a mean score of 276. This test result prompts a state school administrator to declare that the mean score for the state's eighth graders on this exam is more than 270. Assume that the population standard deviation is 31. At a= 0.09, is there enough evidence to support the administrator's claim? Complete parts (a) through (e). (a) Write the claim mathematically and identify Ho...
Question 32 (1 point) A random sample of 40 students has a test score with sample mean 81.5. Assume the population standard deviation is 10.2. Find a point estimate for for the unknown population mean, u if confidence level is 90% 81.5 10.2 (78.783, 84.217) 90% Page 32 of 32 Previous Page Next Page fubmit uit 30 of 37 questions saved
= Question Help For a random sample of 400 students, the mean cost for textbooks during the first semester of college was found to be $374.75, and the sample standard deviation was $30.81. Assuming that the population is normally distributed, find the margin of error of a 95% confidence interval for the population mean The margin of error for a 98% confidence interval is (Round to two decimal places as needed.) I
Students taking a standardized IQ test had a mean score of 98 with a standard deviation of 12. If a random sample of 36 students is selected, find the probability that their mean score is less than 94. Leave your answer as a decimal with 4 decimal places.
random sample of 28 students at the university showed an average age of 25 years and a sample standard deviation of 2 years. Calculate the margin of error for a confidence interval for age at the 98% level of confidence O 1.235 O : 1.645 ○ :0.945 O 0.888
2. A simple random sample of 15 college students showed a mean credit score of 655 and standard deviation 20. Construct the 99% confidence interval estimate of the mean credit score for all college students. a. State the critical value. b. Compute the margin of error. c. State the confidence interval.