Refer to the accompanying technology display. The probabilities were obtained by
ID: 3204925 • Letter: R
Question
Refer to the accompanying technology display. The probabilities were obtained by entering the values of n equals 5n=5 and p equals 0.787p=0.787. In a clinical test of a drug, 78.778.7% of the subjects treated with 10 mg of the drug experienced headaches. In each case, assume that 55 subjects are randomly selected and treated with 10 mg of the drug. Find the probability that at least four of the subjects experience headaches. Is it unusual to have fewer than four subjects experience headaches? LOADING... Click on the icon to view the technology display.
Binomial with
n equals 5n=5
and p equals 0.787p=0.787
x
P(Xequals=x)
0
0.00040.0004
1
0.00810.0081
2
0.05990.0599
3
0.22110.2211
4
0.40860.4086
5
0.30190.3019
x
P(Xequals=x)
0
0.00040.0004
1
0.00810.0081
2
0.05990.0599
3
0.22110.2211
4
0.40860.4086
5
0.30190.3019
Explanation / Answer
Let X be binomial vairbale with n=5 and p=0.787
P(X is at least 4) = P(X=4) + P(X=5)
= 0.4086 + 0.3019 (as displayed)
= 0.7105