Download Using StatCrunch, calculate the chi-square statistic and degrees of

1. Using StatCrunch, calculate the chi-square statistic and degrees of freedom for the
following set of data for 300 people:
Group A Group B Group C Total
Had flu shot 20 30 32 82
Didn’t have flu shot 80 70 68 218
Total 100 100 100 300
Answer: Chi-square statistic is 2 =4.162
Is the value of the chi-square statistically significant at the 0.05 level?
No, because the p-value (0.1248) is greater than  = 0.05
2. Write a paragraph summarizing the results of the analysis in Exercise 1.
Since the chi-square statistic value is not statistically significant at the 0.05 level
We do not have enough evidence to reject the claim that Groups and condition
(having or not flu) are independent
3. Using StatCrunch, calculate the chi-square statistic and degrees of freedom for the
following set of data for 180 people undergoing a knee replacement treatment with a
drug supplement:
Treatment with drug X Treatment without Drug X Total
Had > 8 wk rehab 18 32 50
Had < 8 wk rehab 70 60 130
Total 88 92 180
Answer: Chi-square statistic is 2 =4.603
Is the value of the chi-square statistically significant at the 0.05 level?
Yes, because the p-value (0.0319) is greater than  = 0.05
4. Write a paragraph summarizing the results of the analysis in Exercise 3.
Since the chi-square statistic value is statistically significant at the 0.05 level we
have enough evidence to reject the claim that treatment and time of rehabilitation
are independent.
5. Given each of the following circumstances, determine whether the calculated values
of chi-square are statistically significant:
a. χ2 = 3.02, df = 1, α = 0.05
b. χ2 = 8.09, df = 4, α = 0.05
c. χ2 = 10.67, df = 3, α = 0.01
d. χ2 = 9.88, df = 2, α = 0.01
Critical value is 3.841 , No
Critical value is 9.488 , No
Critical value is 11.345 , No
Critical value is 9.21 , Yes
6. Match each of the nonparametric tests in Column A with its parametric counterpart
in Column B
A. Nonparametric Test B. Parametric Test
1. Mann-Whitney U-test a. Paired t-test
2. Friedman test b. One-way ANOVA
3. Kruskall-Wallis test c. Independent groups t-test
4. Wilcoxon signed-ranks test d. Repeated measures ANOVA
Answer:
1) c)
2) d)
3) b)
4) a)
7. Using the information provided, indicate which statistical test you think should be
used for each of the following situations:
I have doubts about this one
a. Independent variable: normal birth weight vs. low birth weight infants; dependent
variable: 1 minute Apgar scores (1-10 scale).
b. Independent variable: time of measurement (before, during, and after surgery);
dependent variable: heart rate.
c. Independent variable: time of measurement (before, during, and after intervention);
dependent variable: did vs did not exercise regularly.
d. Independent variable: infertility treatment A vs infertility treatment B vs control
condition; dependent variable: did vs did not become pregnant.
8. Below are three sets of expected frequencies for the four cells of 2 X 2 contingency
tables. Identify which statistical procedure would be appropriate for each, using the
most conservative approach.
Do you have options here ?
a. 4 4 b. 35 35 c. 9 9
21 21 65 65 91 91