Find the geometric mean for 8 and 12

What are the equivalent ratios for 24/2= /3= /5.5=108/ = /15

The focus of parabola is (-4, -5), and its directrix is y= -1. fill in the missing terms and signs in parabolas equation in standard form

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