Statistics

Question 44: (2 points)
A nurse measured the blood pressure of each person who visited her clinic. Following is a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. Use the histogram to answer the question. The blood pressure readings were given to the nearest whole number.

* pic attached

Identify the center of the third class.

a. 125
b. 120
c. 130
d. 124

Question 46: (2 points)
Determine whether the given value is a statistic or a parameter.

After taking the first exam, 15 of the students dropped the class.

a. Parameter
b. Statistic

Perform the indicated goodness-of-fit test.

Using the data below and a 0.05 significance level, test the claim that the responses occur with percentages of 15%, 20%, 25%, 25%, and 15% respectively.

Response A B C D E
Frequency 12 15 16 18 19

a. Reject the null hypothesis. There is sufficient evidence to support the claim that the responses occur according to the stated percentages.
b. Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that the responses occur according to the stated percentages.
c. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that the responses occur according to the stated percentages.
d. Fail to reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that the responses occur according to the stated percentages.
'

Find the original data from the stem-and-leaf plot.
Stem Leaves
------------
7.4 1 8
7.5 8 9
7.6 1 9 9

a. 7.41, 7.48, 7.58, 7.59, 7.61, 7.69, 7.69

b. 0.84, 0.84. 1.55, 1.55, 1.65, 0.86, 1.66, 1.67

c. 7.41, 7.42, 7.58, 7.59, 7.65, 7.69, 7.69

d. 0.84, 1.54, 1.55, 1.65, 0.86, 1.66, 1.66

Find the value of the chi-square test statistic for the goodness-of-fit test.

According to recent research, the distribution of the number of children per family in the U.S. is as follows:

Number of children Percent
--------------------------------
More than 3 20.3
3 21.3
2 14.5
1 16.1
0 27.8

A random sample of 700 families with both parents under 40 yielded the following data:

Number of children Number of families
-----------------------------------------
More than 3 154
3 196
2 46
1 101
0 203

You wish to test the claim that the distribution of the number of children per family for families with both parents under 40 is the same as that of the U.S. as a whole. What is the value of the chi-square test statistic? (Note that expected frequencies are as follows: more than 3 children: 142.1; 3 children: 149.1; 2 children: 101.5; 1 child: 112.7; 0 children: 194.6.)

a. χ² = 32.091
b. χ² = 47.674
c. χ² = 13.781
d. χ² = 80.807