2v=3-7
2v=-4 divide both sides
v=-2
7x - (25x^2 + 12x) = 7x - 25x^2 - 12x = -25x^2 - 5x
Answer: z= -1.636
Step-by-step explanation:
When population standard deviation is known, then the test statistic is given by :-

, where
= sample mean,
= population mean, n=sample size ,
= standard deviation
As per given,

Hence, the e test statistic to see whether the candy bars are smaller than they are supposed to be : z= -1.636
There a five terms in this problem.