# Calculating Probabilities from a Table

Classified in Mathematics

Written at on English with a size of 2.5 KB.

## Worksheet: Revisiting Calculating Probabilities from a Table

### 1. Goals

B: Boy1175060227
F: Girl1309130251
Totals24714190| 478

P(F) = 251/478 = 0.525

The probability that a randomly selected student is a girl is 0.525.

P(PC) = (247 + 90)/478 = (478 – 141)/478 = 337/478 = 0.705

The probability that a randomly selected student did not indicate being popular as a primary goal is 0.705.

P(B or S) = (227 + 90 – 60)/478 = 257/478 = 0.538

The probability that a randomly selected student is a boy or indicated a primary goal is to excel at sports or both is 0.538.

P(B and S) = 60/478 = 0.126

The probability that a randomly selected student is a boy and indicated a primary goal is to excel at sports is 0.126.

P(S|B) = 60/227 = 0.264

The probability that a randomly selected student indicated a primary goal is to excel at sports given that the selected student is a boy is 0.264.

P(G|F) = 130/251 = 0.518

The probability that a randomly selected student indicated a primary goal is good grades given that the selected student is a girl is 0.518.

e. i. (251/478)(250/477)(249/476)(248/475)(247/474) = 0.039      ii.   (247/478)(246/477)(245/476)(244/475)(243/474) = 0.036

### 2. Highest Education

Less than High SchoolHigh SchoolMore than High SchoolTotals
Better off1404504201010
Same60250110420
Worse off20030070570
Totals4001000600| 2000
1. 450/1000 = 0.450
2. 1010/2000 = 0.505
3. (400/2000)(399/1999)(398/1998) = 0.008
4. 450/2000 = 0.225
5. 420/1010 = 0.416
6. (1010 + 570)/2000 = (2000 – 420)/2000 = 1580/2000 = 0.79
7. (570/2000)(569/1999)(568/1998)(567/1997) = 0.007
8. (570 + 1000 – 300)/2000 = 1270/2000 = 0.635