Question

1.A report in a research journal states that the average weight loss of people on a certain drug is 23 lbs with a margin of error of ±2 lbs with confidence level C = 95%.

(a) According to this information, the mean weight loss of people on this drug, μ, could be as low as .........lbs.

(b) If the study is repeated, how large should the sample size be so that the margin of error would be less than 1 lbs? (Assume σ= 10 lbs.)

2.Suppose the number of cars in a household has a binomial distribution with parameters n=14n=14 and p=10p=10%.

Find the probability of a household having:

(a) 9 or 12 cars
(b) 10 or fewer cars
(c) 10 or more cars
(d) fewer than 12 cars
(e) more than 10 cars

3.Find the probability of throwing a sum of 11 at least 9 times in 12 throws
of a pair of fair dice.

4. If XX is a binomial random variable, compute P(X=x)P(X=x) for each of the following cases:

(a)  n=6,x=3,p=0.6n=6,x=3,p=0.6
P(X=x)=P(X=x)=

(b)  n=4,x=2,p=0.6n=4,x=2,p=0.6
P(X=x)=P(X=x)=

(c)  n=4,x=2,p=0.8n=4,x=2,p=0.8
P(X=x)=P(X=x)=

(d)  n=4,x=2,p=0.4n=4,x=2,p=0.4
P(X=x)=

5.A report in a research journal states that the average weight loss of people on a certain drug is 2323 lbs with a margin of error of ±2±2 lbs with confidence level C = 95%.

(a) According to this information, the mean weight loss of people on this drug, μμ, could be as low as ........ lbs.

(b) If the study is repeated, how large should the sample size be so that the margin of error would be less than 1 lbs? (Assume σ= 10σ= 10 lbs.)

Answer 1