How many moles of hydrogen are produced from a reaction involving 156.4 g of zinc and excess hydrochloric acid?

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

Erik buys 2.5 pounds of cashews. if each pound of cashews costs $7.70, how much will he pay for the cashews?

Arectangular garden is 5 feet long and 3 feet wide. a second rectangular garden has dimensions that are double the dimensions of the first garden. what is the percent of change in perimeter from the first garden to the second garden?