Answer: First question: D, Second question: A
Step-by-step explanation:
Note: I'm not so good at expanding so I'll just solve it :)
So this leaves either C or D
Apply the sum rule:
8-70=-62
The only one that gives a negative sum is D
For the second picture, the one you have chosen is correct
a1 = 3 and r = -5 so:
an = 3/5 * (-5)^n
Plugging in 8 for n (the first choice) we get the given term: -234,375
If I understand what you are asking, you can use the median as an average since it is not affected by the mean ( median is a measure of center). Since a mean is affected by outliers, it might lower the score if there are very low outliers. But note that if there are outliers way <em>greater </em>it can increase the average. You can use the Inter Quartile Range if shown on a box plot ( measure of variability).
That would be 15/80=3/16 so it would be 3/16 or unlikely because it is less than half of 16