Life for one car model varies Normally with a mean 84 mg/mi and standard deviation 6 mg/mi. A company has 16 cars of this model in its fleet. What is the probability that the average NOX + NMOG level ¯ of these cars is above 90 mg/mi?

probably .5

i can on others if necessary.

given the equation is 8+9z=-6, the first step would be to subtract the 8 from both sides:

8+9z-8=-6-8

since 8 minus 8 = 0, this would cancel out the 8. and since -6 minus 8 equals -14, the equation would look like this

9z = -14