The ratio of Vicki's savings to Donna's savings is 4 : 7. Vicki saved $225 less than Donna. How much money did Vicki save?

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

Richard save $32 in march he saved $48 in april and $38 in may then richard spent $113 on a keyboard how much money does richard have left

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