Data collected at elementary schools in DeKalb County, GA suggest that each year roughly 25% of students miss exactly one day of school, 15% miss 2 days, and 28% miss 3 or more days due to sickness. (a) What is the probability that a student chosen at random doesnt miss any days of school due to sickness this year? (b) What is the probability that a student chosen at random misses no more than one day? (c) What is the probability that a student chosen at random misses at least one day?

Respuesta :

you are given the % so you can go with 100 students. You have 28% 25% and 15%. These add up to 68. 68 out of 100 students miss school at some point. That means 32 never do miss school. 32/100 = reduced is 8/25. 

A. Probability is 8 out of 25

43/100 miss more than 1 day so 57/100 do not 

B. Probability is 57 out of 100

C. opposite of A  17 out of 25
A) 1-(.25+.15+.28) = .32 or 32%
B) 1-(.15+.28) = .57 or 57%
C) .25+.15+.28 = .68 or 68%