Answer
a. $0.335$
b. $0.811$
c. $0.598$
Work Step by Step
The total is 2784
a. The item went to a home. (add numbers under home 934)
P(went to a home)=$934/2784=0.335$
b. The item was an ad, or it went to a business. (all ad 1427, all to business 1850)
P(ad)=$1427/2784=0.513$, P(business)=$1850/2784=0.665$
P( ad and to a business)=$1021/2784=0.367$
P( ad or to a business)=$0.513+0.665-0.367=0.811$
c. The item was a first-class letter, or it went to a home. (all letter 1057, all to home 934)
P(letter)=$1057/2784=0.380$, P(went to a home)=$934/2784=0.335$
P(letter and went to a home)=$325/2784=0.117$
P(letter or went to a home)=$0.380+0.335-0.117=0.598$
