stats questions
1. A random sample of size n = 175 is taken from a population with population proportion P = 0.71.
Calculate the expected value and the standard error for the sampling distribution of the sample proportion.(Round intermediate calculations to 4 decimal places, “expected value” to 2 decimal places and “standard deviation” to 4 decimal places.)
exptected value?
2.Suppose that the miles-per-gallon (mpg) rating of passenger cars is a normally distributed random variable with a mean and a standard deviation of 31.9 and 3.4 mpg, respectively.
a. | If two passenger cars are randomly selected, what is the probability that all of the passenger cars get more than 34 mpg? (Round intermediate calculations to 4 decimal places, “z” value to 2 decimal places, and final answer to 4 decimal places.) probability? |
b. | What is the probability that a randomly selected passenger car gets more than 34 mpg? (Round intermediate calculations to 4 decimal places, “z” value to 2 decimal places, and final answer to 4 decimal places.) probability? |