(a) What is the standard error of X, the mean from a random sample of 9 fill-ups by one driver? (Round your answer to 4 decim places.) Standard error of X (b) Within what interval would you expect the sample mean to fall, with 95 percent probability? (Round your answers to 4 decim places.) The interval is from to

What value of x is two standard deviation to the right of the mean if X - N(10, 1)? 1 2 4 8 10 12

A population of N = 8 scores has a mean of M = 10.  After one score is removed, the mean is found to be M = 5  What is the value of the score that was added? A   X = 45 B   X = 35 C   X = 50 D   X = 80

You determine that the standard deviation for a sample of test scores is 0.  This tells you that 1 all the test scores must be 0. 2 all the test scores must be the same value. 3 there is no straight-line association. 4 the mean test score must also be 0. 5 you made a mistake because the standard deviation can never be 0.

Withdrawal symptoms may occur when a person using a painkiller suddenly stops using it. For a special type of painkiller, withdrawal symptoms occur in 1% of the cases. A random sample of 1100 people who have stopped using the painkiller is going to be taken. Let p be the proportion of people in the sample who experience withdrawal symptoms. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of P. 0 (b) Find the standard deviation of p. 0 (c) Compute an approximation for P<0.02), which is the probability that fewer than 2% of the people in the sample experience withdrawal symptoms. Round your answer to four decimal places. 0 X

A researcher wants to investigate the effects of environmental factors on IQ scores. For an initial study, she takes a sample of 400 people who grew up as the only child. She finds that 51.5% of them have an IQ score over 100. It is known that 50% of the general population has an IQ score exceeding 100. Answer the following. (If necessary, consult a list of formulas.) (a)Find the mean of p, where p is the proportion of people with IQ scores over 100 in a random sample of 400 people.   (b)Find the standard deviation of p.   (c)Compute an approximation for P≥p0.515, which is the probability that there will be 51.5% or more individuals with IQ scores over 100 in a random sample of 400.  Round your answer to four decimal places.

What is the formula for finding the z-score? The z-score of the mean is always Z =

A researcher uses analysis of variance to test for mean differences among three treatments with a sample of n=12 in each statement.The F-ratio for this analysis would have which df values?   df=2,11 df=2,33 df=2,35 df=2,36