Answer: 30
Step-by-step explanation: when you look at the x value of 9, the y value on the best fit line would be 30
Empirical rule dictates that, in a Bell-shaped distribution, 95% of data lies within 2 standard deviation on either side of the mean.
Therefore,
Lower value = mean-2SD = 70-2*8 = 70-16 = 54
Upper value = mean+2SD = 70+2*8 = 70+16 = 86
Then, 95% of the data lies between $54 and 84. These values can also be taken as the true mean of the population considering 95% confidence when sample mean has been calculated. In this regard, 2SD can be regarded as the margin error.
The correct answer is 10.4...
Hope this helps