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 5?% 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 7 major bridges in the? city, at least 3 will have an inspection rating of 4 or below in 2020. ?P(xgreater than or equals≥?3)equals = ?(Round to five decimal places as? needed.)