Why dependent samples t test could be significant and independent t test not for the same numbers Both use the formula t=mean difference/standard error, but the way standard error is calculated is different because in independent samples, you don't have the relationship of paired data you have in the independent test

sample writeups of SPSS results

• One sample t test: "There is a statistically significant difference (t=5.84, df=9, p<.001) in means between the sample (xbar=110.8, x=11) and the hypothesis (xbar = 90)"
• Independent samples t test: "There is no statistically significant difference (t=-1.74, df=8, p>.05) between control (xbar=105, s=12.3) and experimental (xbar=7.5) groups"
• Mann-Whitney: "There is no difference in ranking (z=-1.57, p>.05) between control (xbar rank=4) and experimental (xbar rank=7) groups"
• Null hypothesis: "There is no mean difference between control and experimental groups"

asymptotic is for huge samples in Mann-Whitney results

r = multiple correlation coefficient

The correlation table and the regression's model summary table say the same confidence value (Pearson post versus r)

regression line formula: y = bX + a

don't forget to change the SPSS axis in graphics to start at zero to more accurately represent the data

Looking at assignment 2-3

1. A2; independent t test b/c it's normally distributed (interval/ratio) and has two independent groups B2; Mann-Whitney b/c not normal distribution (ranking) and has two independent groups
2. A2; Wilcoxon b/c not normal distribution & paired/related groups
3. independent sample t test b/c it is interval/ratio and has two independent groups
4. regression (b/c of "predict") bivariate
5. one sample t test b/c one group against hypothesized mean
6. descriptive; pick type based on whether it is interval/ratio, ordinal, etc. There is no null with descriptives
7. nothing is the key word, but independent t is the best b/c dependent variable is interval/ratio and people either have A or C so they are independent (students can't have A and C as a final grade)
8. Spearman's (or Pearson)
9. probably not a good question; could use Wilcoxon or dependent t test
10. regression was the intended test, but could be a Pearson's; Witta says "influence" is a strong word