Let the probability that a customer rates the logo as good be \(p = 0.42\). The number of customers rating the logo as good follows a binomial distribution \(B(n, p)\) where \(n = 10\).
We need to find the probability that fewer than 8 customers rate the logo as good, i.e., \(P(X < 8)\).
This is equivalent to \(1 - P(X \geq 8)\).
Using the binomial probability formula:
\(P(X = k) = \binom{n}{k} p^k (1-p)^{n-k}\)
Calculate \(P(X \geq 8) = P(X = 8) + P(X = 9) + P(X = 10)\).
\(P(X = 8) = \binom{10}{8} (0.42)^8 (0.58)^2\)
\(P(X = 9) = \binom{10}{9} (0.42)^9 (0.58)^1\)
\(P(X = 10) = \binom{10}{10} (0.42)^{10} (0.58)^0\)
Thus, \(P(X \geq 8) = 10C_8 (0.42)^8 (0.58)^2 + 10C_9 (0.42)^9 (0.58)^1 + 10C_{10} (0.42)^{10}\).
Therefore, \(P(X < 8) = 1 - (10C_8 (0.42)^8 (0.58)^2 + 10C_9 (0.42)^9 (0.58)^1 + 10C_{10} (0.42)^{10})\).
Calculating this gives \(P(X < 8) = 0.983\).