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Choose the correct problem formulation: A Statistics Department is contacting al

ID: 3057698 • Letter: C

Question

Choose the correct problem formulation: A Statistics Department is contacting alumni by telephone asking for donations to help fund a new computer laboratory. Past history shows that 80% of the alumni contacted in this manner will make a contribution of at least $50. A random sample of 20 alumni is selected. Let x represent the number of alumni that makes a contribution of at least $50. What is the probability that exactly 15 alumni will make a contribution of at least $50?

P(x <= 15) - P(x<=14)

P(x <=18) - P(x <= 13)

P(x <= 16)

1 - P(x <= 15)

None of the above.

a.

P(x <= 15) - P(x<=14)

b.

P(x <=18) - P(x <= 13)

c.

P(x <= 16)

d.

1 - P(x <= 15)

e.

None of the above.

Explanation / Answer

Choose the correct problem formulation: A Statistics Department is contacting alumni by telephone asking for donations to help fund a new computer laboratory. Past history shows that 80% of the alumni contacted in this manner will make a contribution of at least $50. A random sample of 20 alumni is selected. Let x represent the number of alumni that makes a contribution of at least $50. What is the probability that exactly 15 alumni will make a contribution of at least $50?

P(x <= 15) - P(x<=14)

P(x <=18) - P(x <= 13)

P(x <= 16)

1 - P(x <= 15)

None of the above.

a.

P(x <= 15) - P(x<=14)

b.

P(x <=18) - P(x <= 13)

c.

P(x <= 16)

d.

1 - P(x <= 15)

e.

None of the above.