In: Statistics and Probability
A recent survey found that 22% of all people 16 years of age and older do volunteer work. Suppose a random sample of 350 people 16 years of age and older is taken. What is the probability that more than 24% of the people in the sample do volunteer work?
a) 0.1894 |
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b) 0.8106 |
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c) 0.1841 |
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d) 0.8159 |
Solution
Given that,
p = 22% = 0.22
1 - p = 1 - 0.22 = 0.78
n = 350
= p = 0.22
= p ( 1 - p ) / n
= (0.22 * 0.78) / 350 = 0.0221
= 0.0221
P( > 0.24) = 1 - P( < 0.24)
= 1 - P(( - ) / < (0.24 - 0.22) / 0.0221)
= 1 - P(z < 0.90)
= 1 - 0.8159
= 0.1841
Probability = 0.1841