ch 9 prob 13

Chapter 9 Problem 13: Pseudo-replicated Data
a. Two Sample t-test

data:  female$heart_rate and male$heart_rate
t = 3.6146, df = 118, p-value = 0.0004435
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
  3.828165 13.105168
sample estimates:
mean of x mean of y
 77.53333  69.06667
b. 95% C.I.: mean of differences = 77.53... - 69.06...=8.46... (ellipses = repeating #)
13.105168 - 8.46... = 4.6385014,
C.I. = 8.467 +-4.639

Chapter 9 Problem 13: Independent Data
Two Sample t-test

data:  fem$ave_hr and boy$ave_hr
t = 1.8441, df = 28, p-value = 0.07578      # see the difference in t, df, and p
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -0.9380354 17.8713688          # see diff in interval bounds
sample estimates:
mean of x mean of y
 77.53333  69.06667         # see how means are same as pseudo-replicated data
C.I.: 17.8713688 - 8.46... = 9.4047022
C.I. = 8.467+-9.405
d. t, df, and p value change between data because the data has been averaged
e. the C.I. for the indep. data has a larger area between the upper and lower bounds, and it also passes into the negatives. pseudo-replication creates a narrower margin of error