I know i already asked this but i need the answer Which expression shows the sum 9 + 21 rewritten as a product of the GCF and a sum?

O 9(1 + 21)
O 3(3 + 7)
O 3(3 + 21)
O 9(1 + 3)

What is the length of bc ? enter your answer in the box. bc =

Divide. write in simplest form 41/6 divided by 10

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