Bonferonni adjustments are necessary when making the multiple comparisons because it reduces the chance of making a type I error
True. the Bonferonni adjustment is designed to keep alpha the same level by reducing the the critical p-value for any one (of multiple) comparisons. If each comparison had a p-value of .05 then the chance of making a type 1 error increases with each additional comparison. Without adjustment the probability of making a type I error = 1-.95^(#of comparisons). As the number of comparisons increase the probability of making a type 1 error increases. The Bonferonni adjustment corrects for this.
true
True
false
False
To test all correlated pairs what is the new critical p value after a bonferonni adjustment maintaining an alpha of .05.

(corrpair.gif)
6 comparisons .05/6 = .0083
true
.0083
false
.013
false
05
false
.1
Calculate t for each comparison CA-CB, CB-CC, and CC-CD?.

(corrpair.gif)
false
a. 3.67, 6.00, -2.25
false
b. 2.45,3.50,-3.44
false
c. -3.67, -6.00, 2.25
true
d. -2.45, -3.50, 3.44