Question

The following data gives the information on the observed lifetimes (in hours) of 225 electrical components:

Lifetimes (in hours) 0−20 20−40 40−60 60−80 80−100 100−120
Frequency 10 35 52 61 38 29
Determine the modal lifetimes of the components.

Answer 1

The modal lifetimes of the electrical components, based on the provided frequency distribution, is the 60−80 hours interval, as it has the highest frequency of occurrence (61).

Step-by-step explanation:

To determine the modal lifetimes of electrical components, you need to identify the class interval with the highest frequency. In this data, the intervals are 0−20, 20−40, 40−60, 60−80, 80−100, and 100−120 hours, with their respective frequencies being 10, 35, 52, 61, 38, and 29.

From the given frequencies, we see that the interval 60−80 hours has the highest frequency (61). Therefore, the modal lifetime is the 60−80 hours interval as it occurs most frequently among the components tested.