I need help with this study guide I'm making Flashcards from these Questions, I've Bolded the ones I think are right please correct me if I'm wrong.

1. What is the best interpretation for the following symbol? P

a) population

b) proportion

c) parameter

d) population proportion

2. The standard deviation of the Standard Normal distribution is

a) 0

b) 1

c) 68%

d) cannot be determined with the information given.

3. A waiter estimates that his average tip per person is $2 with a standard deviation of $0.40. If his tables seat 9 customers, the probability that the average tip for one table is less than $2.10 when the tip per person is normally distributed is

a) 0.5987

b) 0.9878

c) 0.7734

d) 0.7266

4. Suppose your instructor is interested in finding out if people like chocolate. He polls one of his classes and asks them "Do you like chocolate?" The result is that 95% of the students from that class said that they liked chocolate. The result of 95% is called a(n)

a) statistic

b) parameter

c) mean

d) area

5. If repeated random samples of size 40 are taken from an infinite population with finite standard deviation, then the distribution of sample means a) will always be normal because we do not know the distribution of the population.

b) will always be normal because the sample mean distribution is always normal.

c) will always be normal because the population is infinite.

d) will be approximately normal because of the Central Limit Theorem. 5

6. Suppose that a very large number of random samples of size 25 are selected from a population with mean Mu and standard deviation sigma . If the mean of all the x values found is 300 and the standard deviation of these x values is 20, then the values of Mu and sigma are, respectively,

a) 300 and 100.

b) 300 and 4.

c) 300 and 20.

d) 300 and 16.

7. A certain brand of light bulb has a mean lifetime of 1500 hours with a standard deviation of 100 hours. Suppose that the bulbs are sold in boxes of 25 and we purchase three boxes (assume this is a random sample of bulbs). If the mean lifetime of the bulbs that we purchased is 1556 hours, then what is the z-score for 1556?

a) 2.800

b) 4.850

c) 0.560

d) 14.00