Question

A researcher was interested in the anxiety present in students just prior to the midterm exam. The research used an anxiety self-quiz to gage the student's anxiety. The score for 30 students are: 69,61,84,99.66.86.91.94,54,66,77,48, 70,70,86,98.56,43,70,88,78,53,85, 40,86,79,58,40,89,70. 1. Construct a frequency table with class, frequency, relative percent and cumulative percent that has 6 classes to describe the distribution of the data. 2. Use the frequency table to construct a histogram. 3. Calculate the numerical descriptive statistics mean, median, standard deviation, and variance of the anxiety scores. Please show all work.

Answer 1

1:

The minimum value: 40

The maximum value: 99

Since we need six classes so width of the class is (99-40) / 6 = 9.8. That is approx 10. Following table shows the frequency distribution:

Interval	Frequency, f	Relative frequency , f/30	Cumulative frequency
40-50	4	0.133333333	4
50-60	4	0.133333333	8
60-70	4	0.133333333	12
70-80	7	0.233333333	19
80-90	7	0.233333333	26
90-100	4	0.133333333	30
Total	30

2:

Following is the histogram of the data:

3:

For descriptive statistics goes to excel Data analysis tool. Select descriptive statistics and then select datat.

Following is the output of descriptive statistics:

Descriptive statistics
	X
count	30
mean	71.80
sample standard deviation	17.25
sample variance	297.41
minimum	40
maximum	99
range	59
1st quartile	58.75
median	70.00
3rd quartile	86.00
interquartile range	27.25
mode	70.00
low extremes	0
low outliers	0
high outliers	0
high extremes	0