Determine the probability that, in a random group of 13 people who purchase a mobile phone, fewer than 11 pick a phone made by Company A.
Use a suitable approximation to work out the probability that, in a random sample of 130 people who buy a mobile phone, at least 50 choose a phone made by Company B.
Determine the probability that, in a random group of $13$ people who purchase a mobile phone, fewer than $11$ pick a phone made by Company A.
Use a suitable approximation to work out the probability that, in a random sample of 130 people who buy a mobile phone, at least 50 choose a phone made by Company B.
A random sample of $n$ mobile phones sold is selected. The chance that at least one of these phones is made by Company B is greater than $0.98$. Determine the least possible value of $n$.