sampling distribution of x, t

Distribution A x frequency 0 20 1 2 2 3 3 2 4 4 5 18 6 5 7 4 8 6 9 6   Distribution B x frequency 0 7 1 6 2 6 3 7 4 8 5 6 6 7 7 9 8 8 9 6   Both samples are the last digits of recorded weights of people.  One of the samples came from measured weights, whereas the other sample resulted from asking people what they weigh.   Identify which distribution came from which sample.  Explain how you came to that conclusion.   Notice that you can make a conclusion about the nature of the data by simply examining the distributions.    Next, construct an “ideal” distribution of last digits x that would result from 100,000 people who were actually weighed.  Estimate the mean and standard deviation of the last digits x in the ideal distribution.   Finally, explicitly agree or disagree with the posts of at least 2 of your peers, and explain why you agree or…

SUBPART, need help solving the problem. Label each part

The Pearson s product moment correlation coefficient (r ) is derived by calculating the ratio of the _____________.     between treatments variability / variability in X and Y separately     variability in X and Y separately / the covariance of X and Y together     between treatments variability / the total variability in the dataset     the covariance of X and Y together / variability of X and Y separately

Random Variable X Directions: Compute the expected value, variance, and standard deviation for random variable X whose probability table is given below: Possible Outcome 8 10 12 14 0.1 0.4 0.4 0.1 Probability Probability Table for X 1. The Expected Value of X is E(X) 2. The Variance of X is Var(X) 3. The Standard Deviation of X is Std(X) Random Variable Y Directions: Compute the expected value, variance, and standard deviation for random variable Y whose probability table is given below: Possible Outcome 8 10 12 14 Probability 0.3 0.2 0.2 0.3 Probability Table for Y 1. The Expected Value of Y is E(Y) 2. The Variance of Y is Var(Y) 3. The Standard Deviation of Y is Std(Y)

Using the Binomial distribution, If n = 9 and p = 0.2, then calculate the following P(x 3) D [three decimal accuracy] Submit Question

t Test for TWO DEPENDENT (Related) SAMPLES (Show all work) A manufacturer of a gas additive claims that it improves gas mileage. A random sample of 40 drivers tests this claim by determining their gas mileage for a full tank of gas that contains the additive (X1) and for a full tank of gas that does not contain the additive (X2). The sample mean difference D-Bar equals 2.12 miles (in favor of the additive) and the estimated standard error equals 1.50 miles. Test the Null Hypothesis with t, using the .05 Level of significance and construct a 95 percent confidence interval (whether you reject OR retain the Null Hypothesis)

The ANOVA F-test is always a  left tailed test two tailed test right tailed test What distribution does the test use? χ2 t z F

Information about a sample is given assume that the sampling distribution is symmetric and bell shaped. X=52 and the standard error is 5

a) Mean b) Binomial Distribution