Basic Applied Statistics 200
Solutions to Midterm 1
-
- (v) [comparing proportion in response of interest (survival) for the two
explanatory groups (banded vs unbanded)]
- (iv) [0.36 is almost twice as high as 0.20]
- 28/100=28%
- 4 [expected count 0.28(50)=14 is 4 more than the observed 10]
- 18+32+10=60
- (iii) [C->Q in a two-sample design]
-
- (i) [Individuals are occupations; for each individual, a pair of values is
recorded---typical women's earnings and typical men's earnings.]
- (v) [Picture the stemplot rotated with 6's on the left and 9's on the
right; there is a somewhat longer right tail, but not extreme.]
- 0 [Because there were no values above 100%.]
- (iii) [The values range from 61 to 96 so 0.1 and 1.0 would be too
small for the typical distance of values from their mean and 100 would be too large.]
-
- (ii) sigma [It's the mean for
the popuation of finches, not a sample.]
- 4, 6, 8, 10, 12, 14, 16
- 14 [mean plus 2 sds]
- 16% [because 68% are between 8 and 12]
- mean - 2.5 sds=10-2.5(2)=5
- (ii) [because it's 1.75 sds above the mean]
-
- (v) [positive and moderately strong; positive square root of 0.638]
- (ii) [the slope]
- (iii) [because the scatter would be reduced and the clustering of points
around a line would be tighter]
- (ii) [The assignment of roles does not affect the correlation but it
does affect the regression line.]
- 34.2+0.0473(1934)=126
- 156-126=30
- (iii) [This is what S tells us.]
-
- (i) ["By taking advantage of a national registry..."]
- (iii) [Before and after makes it paired, comparing women who had abortions
with women who gave birth makes it two-sample.]
- (i) [Abortion: had one or not; mental health: had contact with mental
health professional or not.]
- (ii) [Not (i) because "women do not suffer mental health problems...as
a result of having an abortion..." but (ii) is correct because "Women who had
abortions had higher rates of mental health disorders overall."]
- (iv) [Considering these Danish women as a sample, and using their results
to draw conclusions about the population of all women in the world.]
-
- stress
- (i) [The researchers
lowered stress by reducing unwanted attention, cleaning
the cats' litter boxes, and reducing strange noises. These are not factors
that can be quantified. In fact, they most likely eliminated as many stressors
as possible from cats in the treatment group, so their categorical variable
just had two levels: stress reduced or not.]
[ Home
| Calendar
| Assignments
| Handouts
]
|