The speed of a bus from University A to University B was increased by 20% to 48 miles per hour. What was the speed
of the bus from University A to University B before the
increase?
miles per hour

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