7. Test your self

Controlling variability

1. In the first example, a power analysis was used to show how much sample size could be reduced by housing mice two instead of one per cage (which required 30 mice/gropup). How much was sample size reduced?

From 30 to 18
From 30 to 25
From 30 to 14
From 30 to 12

Correct, 14 mice/group

2. In the second example when sample size was fixed at 20/group the power when using inbred strains ranged from 86->99%. However, when using outbreds the power was reduced to:


Correct, less than 20%

3. In the third example showing the effects of genotype and disease, which class of stock was phenotypically the most uniform

F1 hybrids
F2 hybrids
Outbred stocks Mycoplasma infected

Correct, F1 hybrids