Mean = 40 median = 37.5 mode = 30
You have to move the decimal four (note the exponent) places to the left so the decimal is directly after the first number. You have to drop the zero because it's not significant. The answer is 1.958 x 10^4
Thats for questions 3 - 8 that you didn't answer. I'm not quite sure how to answer the last two though.
Answer:
The slope of the perpendicular line is 1/4
A line parallel to this will have the same gradient of -4.