6 At a company's call centre, \(90 \%\) of callers are connected immediately to a representative.
A random sample of 12 callers is chosen.
- Find the probability that fewer than 10 of these callers are connected immediately.
A random sample of 80 callers is chosen. - Use an approximation to find the probability that more than 69 of these callers are connected immediately.
- Justify the use of your approximation in part (b).