Question 765989
Q:
A national standard requires that public bridges over 20 feet in length must be inspected and rated every two years. The rating scale ranges from 0 (poorest rating) to 9 (highest rating). A group of engineers used a probabilistic model to forecast the inspection ratings of all major bridges in a city. For the 2020 the engineers forecast that 5% of all major bridges in that city will have ratings of 4 or below.
Use the forecast to find the probability that in a random sample of 8 major bridges in the city, at least 3 will have an inspection rating of 4 or below in 2020.
P(x greater than or equal to 3) round to 5 decimal places:
---------------------------------------------------------------------------------
A:
P(X ≥ 3) = {{{sum((matrix(2,1,8,x))(0.05^x)(0.95^(8-x)),x = 3,8)}}} = {{{highlight(0.00579)}}}