Automated security software monitors login attempts for potential breaches. For a specific category of low-risk attempts, the probability that the software fails to flag the attempt is 0.06. A security audit reviews these attempts in independent blocks of 50.
Determine the probability that a single block of 50 contains no more than 2 unflagged attempts.
The auditor evaluates 12 such independent blocks. Find the probability that fewer than 3 of these blocks contain at most 2 unflagged attempts.
Using a suitable approximation, estimate the probability that the total number of unflagged attempts across the 12 blocks is more than 45.
67 exam-style questions on Edexcel A Level Maths 3.6 Approximating a Binomial Distribution. Each one has a worked solution and a mark scheme showing where the marks go.