Let "X=" the number of upheld challenges: "X\\sim B(n,p)."
Given that "p=0.25,n=879." Then
We can use a Normal Distribution to approximate a Binomial Distribution
"X^*\\sim N(219.75,164.8125)"
Then
Find the probability that among the 879 challenges last year 231 or more were upheld
"=1-P\\big(Z<{231-219.75 \\over\\sqrt{164.8125}}\\big)\\approx1-0.80956906="
"=0.19043094"
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