Question

The back-to-back stemplot shows the lifetimes of several Brand X and Brand Y batteries.

Part (a). What is the longest that any battery lasted?

Part (b). Give a reason someone might prefer a Brand X battery.

Part (c). Give a reason someone might prefer a Brand Y battery.

Short answer

Part (a) 500 to 599 hour

Part (b) its minimum battery life (300 hours) is longer than that of brand Y. ( 170 hour)

Part (c) because the majority of brand X batteries have a longer lifespan than the majority of brand X batteries.

Step-by-step solution

 Part (a) Step 1. Given information.

The back-to-back stemplot shows the lifetimes of several Brand X and Brand Y batteries.

 Part (a) Step 2. What is the longest any battery has ever lasted?

The longest time is shown at the very bottom of the stemplot: 515, which corresponds to 500 to 559 hours.

As a result:

500 to 599 hour

 Part (b) Step 1. Reason someone might prefer a Brand X battery. 

You might prefer brand X because its minimum battery life (300 hours) is longer than that of brand Y. ( 170 hour)

 Part (c) Step 1. Reason someone might prefer a Brand Y battery. 

You might prefer brand Y because the majority of brand X batteries have a longer lifespan than the majority of brand X batteries.