Each multiple choice/short answer question is worth 3 points. Show your work where necessary. If you use a calculator, please write the function used. For example "binomcdf(10,0.5,5)" or "normalcdf(- E99,10,25,2)". If you use a formula and table, please show the formula or any calculations used. 1. For the standard normal distribution, the mean is: __________. 2. For the standard normal distribution, the standard deviation is: ___________. 3. Sketch the standard normal probability distribution and shade the region that represents P( z < 1.1). Do not find this probability. 4. A student claims that, on average, tuition is less than $150 per credit hour, on average, in the United States. Write the null and alternative hypotheses which would be used to test this statement. 0 :H________ :aH________ 5. The results of a recent study show that the proportion of people in the United States who use seatbelts when riding in a car or truck is larger than 81%. Write the null and alternative hypotheses which would be used to test this statement. 0 :H________ :aH________ 6. Find ( 1.2)PZ

7. In general, a normal distribution has which of the following properties? a) the mean, median, and mode all equal b) bell shaped and symmetric c) the total area under the curve is 1 d) all of the above 8. The household income in a certain community is normally distributed with a mean of $42,000 and a standard deviation of $5,000. If X represents the household income for a randomly selected house in this community, which of the following represent the probability the household's income is greater than $38,000? Do not find this probability. a) ( 38000)PX b) ( 38000)PX c) (38000 42000)PX d) None of these 9. Given P = 0.085. Do you reject or fail to reject at the 0.05 level of significance? A) fail to reject H0 B) reject H0 C) not sufficient information to decide 10. A nurse at a local hospital is interested in estimating the mean birth weight of infants. How large a sample must she select if she desires to be 90% confident that the true mean is within 3 ounces of the sample mean? The standard deviation of the birth weights is known to be 6 ounces. 11. In number 10 above, what would be the units on your answer? (i.e. what are they sampling?) a) ounces b) hospitals c) local hospitals d) infants e) none of these