Answer the following questions: Jackson even-numbered Chapter Exercises (pp XXXXXXXXXX; XXXXXXXXXX) What are degrees of freedom? How are the calculated? What do inferential statistics allow you to...

9
Answer the following questions:
1. Jackson even-numbered Chapter Exercises (pp. 220-221; 273-275)
2. What are degrees of freedom? How are the calculated? 
3. What do inferential statistics allow you to infer?
4. What is the General Linear Model (GLM)? Why does it matter?
5. Compare and contrast parametric and nonparametric statistics. Why and in what types of cases would you use one over the other?
Jackson even-numbered Chapter Exercises (pp. 220-221; 273-275)
Chapter 8/pp. 220-221
2) The producers of a new toothpaste claim that it prevents more cavities that other
ands of toothpaste. A random sample of 60 people used the new toothpaste for 6 moths. The mean number of cavities at their next checkup is 1.5. In the general population, the mean number of cavities at a 6-month checkup is 1.73 (σ = 1.12).
a. Is this a one- or two-tailed test?
This is one-tailed test.
. What are H0 and Ha for this study?
H0: ( = 1.73
Ha: ( < 1.73
c. Compare Zobt
Zobt = ((60((1.5 – 1.73))/1.12 = -1.59
d. What is Zcv?
Zcv = -1.65
e. Should H0 be rejected? What should the researcher conclude?
As Zobt > Zcv, the null hypothesis can be accepted. The researcher should conclude that the new toothpaste does not prevent more cavities.
f. Determine the 95% confidence interval for the population mean, based on the sample mean.
The 95% confidence interval for the population mean is (1.21661, 1.78339).
4) Henry performed a two-tailed test for an experiment in which N=24. He could not find his table of t critical values, but he remembered the tcv at df = 13. He decided to compare his tobt with this tcv. Is he more likely to make Type I or Type II e
or in this situation?
He is more likely to make Type I e
or in this situation.
6) a researcher hypothesizes that individuals who listen to classical music will score differently from the general population on a test of spatial ability. On a standardized test of spatial ability. Μ = 58. A random sample of 14 individuals who listen to classical music is given the same test. Their scores on the test are 52, 59, 63, 65, 58, 55 62, 63, 53, 59, 61, 60, 59.
a. Is this a one- or two-tailed test?
This is a two-tailed test.
. What are H0 and Ha for this study?
H0: ( = 58
Ha: ( ≠ 58
c. Compare tobt
tobt = ((13(( 59.15 – 58))/3.91 = 1.06
d. What is tcv?
tcv = 2.179
e. Should H0 be rejected? What should the researcher conclude?
The null hypothesis should be accepted. The researcher should conclude that listen to classical music will not score differently.
f. Determine the 95% confidence interval for the population mean, based on the sample mean.
The 95% confidence interval for the population mean is (56.7895, 61.5181).
8) A researcher believes that the percentage of people who exercise in California is greater than the national exercise rate. The national rate is 20%. The researcher gathers a random sample of 120 individuals who live in California and finds that the number who exercises regularly is 31 out of 120.
a) What is X2obt?
X2obt = (0.258 – 0.2)/(((0.2((1 – 0.2))/120) = 1.588
) What is the df for this test?
c) What is X2cv?
X2cv = 1.65
d) What conclusion should be drawn from these results?
The null hypothesis can be...