13.8 Review

What is the probability of both a drought and water rationing occurring?

Out of the years with water rationing, find the probability that there is a drought.

Suppose that one individual is randomly chosen. Find the probability that the person’s favorite pie is apple or the person is male.

Suppose that one male is randomly chosen. Find the probability his favorite pie is pecan.

Conduct a hypothesis test to determine if favorite pie type and gender are independent.

We randomly survey 14 people. On average, how many people do we expect to watch the news at least once per week?

We randomly survey 14 people. Of interest is the number that watch the news at least once per week. State the distribution of $X$ . $X$ ~

The following histogram is most likely to be a result of sampling from which distribution?

• A Chi-Square
• B Geometric
• C Uniform
• D Binomial

The ages of De Anza evening students is known to be normally distributed with a population mean of 40 and a population standard deviation of 6. A sample of 6 De Anza evening students reported their ages (in years) as: 28; 35; 47; 45; 30; 50. Find the probability that the mean of 6 ages of randomly chosen students is less than 35 years. Hint: Find the sample mean.

Find the probability that one customer spends less than $72 in one trip to the supermarket?

Suppose 5 customers pool their money. (They are poor college students.) How much money altogether would you expect the 5 customers to spend in one trip to the supermarket (in dollars)?

State the distribution to use if you want to find the probability that the mean amount spent by 5 customers in one trip to the supermarket is less than $60.

A math exam was given to all the fifth grade children attending Country School. Two random samples of scores were taken. The null hypothesis is that the mean math scores for boys and girls in fifth grade are the same. Conduct a hypothesis test.

In a survey of 80 males, 55 had played an organized sport growing up. Of the 70 females surveyed, 25 had played an organized sport growing up. We are interested in whether the proportion for males is higher than the proportion for females. Conduct a hypothesis test.

Which of the following is preferable when designing a hypothesis test?

• A Maximize $\alpha$ and minimize $\beta$
• B Minimize $\alpha$ and maximize $\beta$
• C Maximize $\alpha$ and $\beta$
• D Minimize $\alpha$ and $\beta$

Are the events of milk and 30+ :

• a Independent events? Justify your answer.
• b Mutually exclusive events? Justify your answer.

Suppose that one person is randomly chosen. Find the probability that person is 10 – 19 given that he/she prefers juice .

Are Preferred Beverage and Age independent events? Conduct a hypothesis test.

Given the following histogram, which distribution is the data most likely to come from?

• A uniform
• B exponential
• C normal
• D chi-square