Six times one number added to another number is 36. Three times the first number minus the other number is 9. Let x be the cost of the small candles and y be the cost of the large candles.​

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