Members at a yodeling school pay $10 per class plus an annual $100 membership fee. Non-members pay $15 per class. If you plan on taking 25 classes a year, is it worth the $100 investment to become a member? Show your thinking and be sure to define any variables used. Need help, please!

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