suppose our sample mean xbar=5, our standard error SE=3, and we are justified in using the normal distribution. which interval should we use if we want a confidence level of 0.997
suppose our sample mean xbar=5, our standard error SE=3, and we are justified in using the...
This question is based on Ch10, but we can solve it using our knowledge from Ch9. In Ch 8, we created confidence intervals to test whether the means differed in a statistically significant manner between two independent (unrelated) populations, like males and females. The sample point estimator in the confidence interval was the difference in the sample means between the 2 samples (xbar - ybar). We created a confidence interval of the form: (xbar-ybar) +/- (Zα/2)[standard error of (xbar-ybar)] We...
Suppose for a study, sample standard deviation s = 5, sample mean xbar = 25 and n = 10. Test the hypothesis that the population mean is different from 24 at 10% significance level.
A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) x = 33, n = 25, C = 6, confidence level = 90% Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table a. Use the one-mean z-interval procedure to find a confidence interval for the mean of the population from which the sample...
Part B
A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) below. x=52, n = 13,0-6, confidence level = 99% Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. a. Use the one mean z-interval procedure to find a confidence interval for the mean of the population from which the sample was...
1. Which formula gives the standard error for all xbar values? _______ a) σ/√n b) σ c) npq d) pq/n e) 1.96σ/√n 2. Prof. Gersch knows that the score on a standardized test is perfectly normal with a mean of 200 and a standard deviation of 40. He then takes a random sample of 16 tests. Prof Gersch wants to check the probability that the average of these 16 tests is less than 210. Which of these is equivalent to the probability...
2. Suppose we want to test Ho: p-0.5 vs Hs: p>0.5 using a sample proportion of 520 out of 1000, or 0.52. . Use a randomization distribution to find the p-value: .What is the standard error from the randomization distribution? Model the randomization distribution with a normal distribution with mean 0.5 from the null hypothesis and standard deviation equal to this standard error. Find the p-value by finding the area to the right of o.56 in this normal distribution Find...
For confidence interval computations, if the sample size is increased, we expect the margin of error to: a. Increase b. Decrease c. stay the same The company you work for produces automotive parts for GM. A certain machine that makes a cutout in a piece of steel averages a cut size of 203.2085 mm with a standard deviation of 0.2083 mm. A random sample of 66 is taken from the population. What is the distribution of the sample mean? Approximately...
Suppose that a committee is studying whether or not there is waste of time in our judicial system. It is interested in the mean amount of time individuals waste at the courthouse waiting to be called for jury duty. The committee randomly surveyed 81 people who recently served as jurors. The sample mean wait time was 7 hours with a sample standard deviation of 2.3 hours. # Part (a) O Part (b) Which distribution should you use for this problem?...
A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) below. x overbarx equals=25, n equals=38, sigma σ equals=4 confidence level equals=95% Click here to view page 1 of the standard normal distribution table. LOADING... Click here to view page 2 of the standard normal distribution table. LOADING... . Use the one-mean z-interval procedure to find a confidence interval for the mean of the population from which the...
A) Suppose we wish to test our
claim that the mean number of ounces of peanuts in a jar is 16
using our confidence interval. Is 16 a reasonable value for the
population mean? Why or why not?
B) A normal probability plot (Q-Q plot) of the sample data is
given below. This plot shows some departure from the straight line.
Is our confidence interval still valid? Why or why not?
Normal Q-Q Plot of Jar Contents Expected Normal Value...