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A health psychologist was researching the role of choice in food consumption. In one experiment, the psychologist offered a group of children a choice of either a chocolate chip cookie or fresh fruit. Earlier results indicate that 63%63\% of children choose the chocolate chip cookie. If the earlier results are accurate, and the psychologist randomly picks 44 children to interview after the experiment, what is the probability that exactly 22 of the children chose the chocolate chip cookies? Write your answer as a decimal rounded to the nearest thousandth____.

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Q. A health psychologist was researching the role of choice in food consumption. In one experiment, the psychologist offered a group of children a choice of either a chocolate chip cookie or fresh fruit. Earlier results indicate that 63%63\% of children choose the chocolate chip cookie. If the earlier results are accurate, and the psychologist randomly picks 44 children to interview after the experiment, what is the probability that exactly 22 of the children chose the chocolate chip cookies? Write your answer as a decimal rounded to the nearest thousandth____.
  1. Use Binomial Probability Formula: Use the binomial probability formula: P(X=k)=C(n,k)(p)k(1p)(nk)P(X = k) = C(n, k) \cdot (p)^k \cdot (1-p)^{(n-k)} Here, n=4n = 4 (number of children), k=2k = 2 (number of children choosing cookies), and p=0.63p = 0.63 (probability of choosing cookies).
  2. Calculate Combination C(4,2)C(4, 2): Calculate C(4,2)C(4, 2) using the combination formula C(n,k)=n!k!(nk)!C(n, k) = \frac{n!}{k!(n - k)!}.C(4,2)=4!(2!(42)!)C(4, 2) = \frac{4!}{(2! \cdot (4 - 2)!)}C(4,2)=(4321)(2121)C(4, 2) = \frac{(4 \cdot 3 \cdot 2 \cdot 1)}{(2 \cdot 1 \cdot 2 \cdot 1)}C(4,2)=6C(4, 2) = 6
  3. Calculate (0.63)2(0.63)^2: Calculate (0.63)2(0.63)^2 for the probability of 22 children choosing cookies.\newline(0.63)2=0.63×0.63(0.63)^2 = 0.63 \times 0.63\newline(0.63)2=0.3969(0.63)^2 = 0.3969
  4. Calculate (10.63)(42)(1 - 0.63)^{(4 - 2)}: Calculate (10.63)(42)(1 - 0.63)^{(4 - 2)} for the probability of the other 22 children not choosing cookies.\newline(10.63)(42)=(0.37)2(1 - 0.63)^{(4 - 2)} = (0.37)^2\newline(10.63)(42)=0.37×0.37(1 - 0.63)^{(4 - 2)} = 0.37 \times 0.37\newline(10.63)(42)=0.1369(1 - 0.63)^{(4 - 2)} = 0.1369
  5. Multiply Values to Find Probability: Multiply all the values together to find the probability.\newlineP(X=2)=6×0.3969×0.1369P(X = 2) = 6 \times 0.3969 \times 0.1369\newlineP(X=2)=6×0.05432721P(X = 2) = 6 \times 0.05432721\newlineP(X=2)=0.32596326P(X = 2) = 0.32596326

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