Answer:The correct option is a)
The upper limit of successes that would be deemed to be usual is 5, so more than 5 successes would be unusual.
Step-by-step explanation:
The mean of a binomial distribution
μ= np where n=10 and p= 0.2 q= 1-p, q= 1-0.2=0.8
μ= 10×0.2=2
σ=√npq
σ=√10×0.2×0.8=1.26
Is unusual for the number of success to be greater than μ + 2.5σ.
= 2+2.5(1.26)
=5 approximately.
So it is unusual for it to be greater than 0.5. The right option Is a)
10.5+(10.5*.4)=10.5+(4.2)=14.7lbs after the first month
