Question

seat-belt usage across different road types
road type yes no total
highway 70 30 100
city 50 50 100
rural 60 40 100
total 180 120 300
what is the conditional frequency of seat-belt usage among drivers on city roads?
50%
50
70%
70

Explanation:

Step1: Recall Conditional Frequency Formula

Conditional frequency for a category (seat - belt usage "Yes" for city roads) is calculated as the number of "Yes" responses for city roads divided by the total number of drivers on city roads. The formula is $\text{Conditional Frequency}=\frac{\text{Number of Yes (City)}}{\text{Total (City)}}$.

Step2: Identify Values from Table

From the table, for city roads, the number of drivers who used seat - belts (Yes) is 50, and the total number of drivers on city roads is 100.

Step3: Calculate Conditional Frequency

Substitute the values into the formula: $\frac{50}{100} = 0.5$ or 50%.

Answer:

50%