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:

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)

47.28 or 47.2857143

step-by-step explanation:

you just divide 331 by 7 and you get that answer. ( i think so tho)