The Fast Food Association of America claims that 57% of
adults age 18-29 eat fast food at least once a week. Suppose
0.57 is the population proportion p of adults age 18-29 that
eat fast food at least once a20%
week.20% 20% 20% 20%
In a sample of n=200 adults age 18-29, let pˆ be the sample
proportion that ate fast food in the past week. What is E ( pˆ ) ?
10
1.
2.
3.
4.
5.
0.43
114
0.57
86
0.2451
1.
2
3.
4
5.
The Fast Food Association of America claims that 57% of
adults age 18-29 eat fast food at least once a week. Suppose
0.57 is the population proportion p of adults age 18-29 that
eat fast food at least once a week.
In a sample of n=200 adults age 18-29, let pˆ be the sample
proportion that ate fast food in the past week. What is SD( pˆ ) ?
10
1.
2.
3.
4.
25%
25%
25%
2.
3.
25%
0.57
0.00122
0.035
0.2451
1.
4.
Sixteen percent of Americans do not have health
insurance. In a random sample of n=500 Americans,
what is the probability that the proportion pˆ that do
not have health insurance is more
20% than
20% 0.20?
20%
20%
20%
10
1.
2.
3.
4.
5.
.0074
.9927
.80
.003
.045
1.
2.
3.
4.
5.
Determine E(X) from the given parameters of the
population and the sample size.
μ = 84 SD(X) = 12 n = 30
10
1.
2.
3.
4.
25%
25%
25%
2.
3
25%
12
5.477
84
15.336
1
4.
Determine SD(X) from the given parameters of the
population and the sample size.
μ = 84 SD(X) = 12 n = 30
10
1.
2.
3.
4.
25%
25%
25%
2.
3.
25%
12
5.477
15.336
2.191
1
4.
A 2008 study of concussions at VA Tech concluded that
in a season college football players suffered an average
of 50 strong blows to the head with a standard
deviation of 16. What is the probability
that a25%
random
25%
25%
25%
sample of 60 college football players results in a sample
mean of 48 or fewer strong blows?
10
1.
2.
3.
4.
0.1665
0.8335
0.3335
0.1858
1.
2.
3.
4.
The VP of quality control at Long John Silver’s wants
drive-thru waiting times to be 60 seconds or less.
Records obtained from the restaurants indicate that
waiting times are skewed right 25%
with mean
25% 58.3
25%seconds
25%
and standard deviation 13.1 seconds. What is the
probability that a random sample of 40 cars results in a
sample mean time of 60 seconds or less?
10
1.
2.
3.
4.
0.5576
0.7941
0.2059
0.500
1.
2.
3.
4.