At a school's open house, T-shirts and sweatshirts were sold.
Each item was purchased by either a student or a parent.
The two-way frequency table summarizes a random sample of 70 items sold that night.
T-shirt
Sweatshirt
Student
18
17
Parent
21
14
Let T-shirt be the event that an item randomly chosen from among those sold was a T-shirt.
Let parent be the event that an item randomly chosen from among those sold was purchased by a by parent
Find the following probabilities. Write your answers as decimals.