A Harris Interactive national telephone poll in 2002 asked, \"Do you think adult

Question

A Harris Interactive national telephone poll in 2002 asked, "Do you think adults should be allowed to legally use marijuana for medical purposes, if their doctor prescribes it, or do you think that marijuana should remain illegal even for medical purposes." The results showed that 80 percent of respondents answered, "Yes, it should be legal for medical purposes." (Ref: A Time & CNN Survey) Assuming that this accurately reflects national attitudes, find the probability when eight Americans are chosen at random:

a. Exactly four said "Yes."

b. Six or fewer said "Yes

Explanation / Answer

n =8

p = 0.8

a)

P(X =4) = 8C4 * 0.8^4 * 0.2^4

= 0.0459

b)

P(X<=6) = 1 - P(X >6)

= 1 - P(X=7) + P(X=8)

= 1 - 8C7 * 0.8^7 * 0.2 - 8C8 * 0.8^8

= 0.4967

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.