Determine the sample size required to estimate a population mean to within 9 units given that the population standard deviation is 60. A confidence level of 90% is judged to be appropriate.

The sample size must be approximately 120.    

Step-by-step explanation:

We are given the following in the question:

Margin of error,E = 9

Standard Deviation, σ = 60

90% confidence level

Sample size is given by:

Putting values, we get,

Thus, the sample size must be approximately 120.

i would have to say it is c.

the answer is d

step-by-step explanation:

y+3=-4(x-2)

y+3=-4x+8

  -3         -3  

y=-4x+5