(i) The two conditions for a binomial distribution are:
- There are a fixed number of trials.
- Each trial is independent.
- There are only two possible outcomes for each trial.
- The probability of success is constant for each trial.
(ii) Let the random variable \(X\) represent the number of cars made by Ford. \(X\) follows a binomial distribution with parameters \(n = 14\) and \(p = 0.28\).
We need to find \(P(X < 4)\), which is the sum of probabilities \(P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)\).
Using the binomial probability formula:
\(P(X = k) = \binom{n}{k} p^k (1-p)^{n-k}\)
Calculate each probability:
\(P(X = 0) = \binom{14}{0} (0.28)^0 (0.72)^{14} = 0.72^{14} = 0.0101\)
\(P(X = 1) = \binom{14}{1} (0.28)^1 (0.72)^{13} = 14 \times 0.28 \times 0.72^{13} = 0.0548\)
\(P(X = 2) = \binom{14}{2} (0.28)^2 (0.72)^{12} = 91 \times 0.28^2 \times 0.72^{12} = 0.1385\)
\(P(X = 3) = \binom{14}{3} (0.28)^3 (0.72)^{11} = 364 \times 0.28^3 \times 0.72^{11} = 0.2154\)
Summing these probabilities gives:
\(P(X < 4) = 0.0101 + 0.0548 + 0.1385 + 0.2154 = 0.419\)