A random sample of 100 students is selected from a certain school. They are given an IQ test which has a known population standard deviation of 11. The sample mean is found to be 112.
What type of inference procedure is appropriate here? Why?
The sample size is greater than 30 and we know the population standard deviation. Hence,
The appropriate inference procedure will be z test for single sample mean.
A random sample of 100 students is selected from a certain school. They are given an...
It is known that IQ of students at a certain elementary school is normally distributed with mean μ = 100 and standard deviation σ = 16. Calculate the probability that in a random sample of n = 4 students the observed sample mean is within 10 units of the true population mean. Answer to four decimal places.
A principal at a specific school thinks that his students are above average intelligence. He collects a random sample of IQ scores from 25 students from his school. His sample has a mean of 112. The mean population IQ is 100 with a standard deviation of 15. Does he have enough evidence to support his claim?
A random sample of 61 fifth grade students was selected and
given the Stanford-Binet IQ test. The mean score for the sample was
97, with an estimated standard error of the mean of 2.43. Estimate
whether the sample mean could be representative of a population
whose mean is 100.
help please. step by step so that i could understand the
process.
HD backlit display 5. A random sample of 61 fifth grade students was selected and given the Stanford-Binet IQ...
The average starting salary of a random sample of 100 high school students was found to be $31,840. The population standard deviation for all such individuals is known to be $9,840. (12) Ten years ago, the average starting salary was $25,000. Does the sample data support the claim that the starting salary for this group has increased? Use alpha = 0.05. (6) Describe in general Type I and Type II errors and the Power of the test. (6) Describe in...
(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...
Suppose you wish to determine if the mean IQ of students on a certain campus is different from the mean IQ in the general population, 100. To conduct this study, you obtain a simple random sample of 80 students on this campus, administer an IQ test, and record the results. The mean IQ of the sample of 80 students is found to be 108.5 with a standard deviation of 12.9. Complete parts (a) through (c) below. Determine the critical value(s)...
A random sample of n = 100 elementary school students were asked how many summer camps they have been in a certain year. This sample yielded a mean of 3.2 and a standard deviation of 1.6. How many standard errors from the null hypothesis value of 3 is the sample mean of 3.2? 2.33 1.25 2.58 1.69
A random sample of 50 students is selected and it is found that the mean of daily internet usage is 70.8 minutes with standard deviation of 13.8 minutes. A hypothesis test was performed to determine whether the true mean usage, µ equal to 72.0 minutes or not. What is the p-value of the test?
A random sample of 64 second-graders in a certain school district are given a standardized mathematics skills test. The sample mean score is 51.57. Assume the standard deviation for the population of test scores is 15. The nationwide average score on this test is 50. The school superintendent wants to know whether the second-graders in her school district have greater math skills than the nationwide average. Perform the hypothesis test and compute the P value. Write down your P.value. You...
2. A random sample of 100 graduates of a certain secretarial school typed an average of 90 words per minute with a sample standard deviation (s) of 10 words per minute. We assume a normal distribution for the number of words typed per minute. (a) (4pts) Find a 95% confidence interval for the average number of words t yped per minute of all graduates of this school. (b) (3pts) Suppose the population standard deviation (o) is exactly 10 words per...