22. A study by the National Park Service revealed that 50% of the vacationers going to the Rocky Mountain region visit Yellowstone Park, 40% visit the Grand Tetons, and 35% visit both. What is the probability that a vacationer will visit at least one of these magnificent attractions?

23. What is the median of 26, 30, 24, 32, 32, 31, 27, and 29?

24. The ages of all the patients in the isolation ward of the hospital are 38, 26, 13, 41, and 22. What is the population standard deviation?

26. The Director of Golf for a local course wants to study the number of rounds played by members on weekdays. He gathered the sample information shown below for 520 rounds. At the .05 significance level, is there a difference in the number of rounds played by day of the week?

Day Rounds

Monday 124

Tuesday 74

Wednesday 104

Thursday 98

Friday 120

Answers:

Yes, because 2 = 12.288

Yes, because 2 = 15.308

No, because 2 = 7.715

No, because 2 = 11.793

27. When statisticians analyze sample data in order to draw conclusions about the characteristics of a population, this is referred to as:

Data analysis

Statistical inference

Data summarization

Descriptive statistics

28. An example of a qualitative variable is _________________.

Color of ink in a pen

Weight of a person

Miles between oil changes

Number of children in a family

29. As the size of the sample increases, what happens to the shape of the distribution of sample means?

It cannot be predicted in advance.

It is positively skewed.

It approaches a normal distribution

It is negatively skewed

30. A research firm conducted a survey to determine the mean amount steady smokers spend on cigarettes during a week. A sample of 64 smokers revealed that = $20 and S = $5. What is the 95% confidence interval for ?

$18.60 to $21.40

$18.78 to $21.23

18.37 to 21.63

18.16 to 21.84