78% of cows on a farm are pregnant. If 5 cows are chosen at random, what is the probability that exactly 3 are pregnant? Write your answer as a decimal rounded to the nearest thousandth. ____
Q. 78% of cows on a farm are pregnant. If 5 cows are chosen at random, what is the probability that exactly 3 are pregnant? Write your answer as a decimal rounded to the nearest thousandth. ____
Use Binomial Probability Formula: Use the binomial probability formula: P(X=k)=C(n,k)⋅(p)k⋅(1−p)(n−k). Here, n=5, k=3, and p=0.78.
Calculate C(5,3): Calculate C(5,3) using the formula k!(n−k)!n!. So, C(5,3)=3!(5−3)!5!=2×15×4=10.
Compute (0.78)3: Compute (0.78)3 which is 0.78×0.78×0.78=0.474552.
Calculate (1−0.78)(5−3): Calculate (1−0.78)(5−3) which is (0.22)2=0.0484.
Multiply Values Together: Now, multiply all the values together: P(X=3)=10×0.474552×0.0484=0.229776768.
Round to Nearest Thousandth: Round the answer to the nearest thousandth: 0.229776768 rounds to 0.230.
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