A national standard requires that public bridges over feet in length must be inspected and rated every 2 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 year 2020, the engineers forecast that % of all major bridges in that city will have ratings of 4 or below. Complete parts a and b. a. Use the forecast to find the probability that in a random sample of major bridges in the city, at least 3 will have an inspection rating of 4 or below in 2020. P(x3) nothing (Round to five decimal places as needed.)

The answer is below

Step-by-step explanation:

A national standard requires that public bridges over 20 feet in length must be inspected and rated every 2 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 year 2020, the engineers forecast that 4%of all major bridges in that city will have ratings of 4 or below.

a. Use the forecast to find the probability that in a random sample of major bridges in the city, at least 3 will have an inspection rating of 4 or below in 2020.

This problem is a probability binomial distribution and it can be solved using the formula:

Hence the solution to the problem is given as:

P(x ≥ 3) = 1 - P(x < 3) = 1 - [ P(x=0) + P(x=1) + P(x = 2)]

Given that p = 4% = 0.04, q = 1 - p = 1 - 0.04 = 0.96, n = 10. Hence:

< 4, -5>

step-by-step explanation:

starting from g. we move 4 right and then 5 down to get to h. that means the vector is < 4, -5>