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Kiera is contacting the poll workers from the last election to see whether they are willing to work in the next election. During the last election, 42\%42%42, percent of the poll workers were under 606060 years old. Let WWW be the number of poll workers Kiera contacts before reaching one that is 606060 years old or older. Assume that each poll worker's age is independent. Find the mean and standard deviation of WWW. Round your answers to one decimal place.

Respuesta :

Answer:

1.7 and 1.1

Step-by-step explanation:

Answer:

Mean: 1.7 and standard deviation 1.1.

Step-by-step explanation:

42% Of the poll workers are less than 60 years old. In other words, 58% of the poll workers are 60 years old: 1-0.42 = 0.58. So W is a geometric variable where the first "success" is poll worker who is at least 60years old.

Mean: 1/0.58 = 1.7241 poll workers, about 1.7 poll workers.

Standard deviation: sqr(1-p)/p = sqr(1-0.58)/0.58 = 1.1174 poll workers, about 1.1 poll workers.

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