For a proof by induction of the math statement below, identify the correct step for proving the theorem is true for n = k + 1. HELP ASAP!!

The average human heart beats 72 beats per minute. how many times does it beat in 15 seconds?

If 25% of y is 30, what is 60% of y?

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics