What are the steps to multiplying a decimal times a decimal?

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

The wheels of a bicycle have a diameter of 70cm. how many meters will the bicycle travel if each wheel makes 50 revolutions

Secant be and cf intersect at point d inside a what is the measure of cde