Refer to the accompanying technology display. the probabilities were obtained by entering the values of n equals 5 and p equals 0.774. in a clinical test of a drug, 77.4% of the subjects treated with 10 mg of the drug experienced headaches. in each case, assume that 5 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?

The probability table is attached below

The probability that at least four of the subjects experience headaches.

Probability of at least 4 means x is greater than or equal to 4

Given n= 5 so we find probability (x=4) and (x=5)

P(x>=4) = P(x=4) + P(x=5)

Given P(x=4) is 0.3732

Also P(x=5) is 0.1882

P(x>=4) = P(x=4) + P(x=5)

= 0.3732 + 0.1882 = 0.5614

the probability that at least four of the subjects experience headaches is 0.5614

(b) No​, it is not unlikely that the probability fewer than four subjects will experience​ headaches