THE BACK STORY-
As the only maths detective in the neighbourhood you have been called in to solve a puzzle. You're feeling nervous- you didn't bother to do any homework leading up to this case, and your reputation is on the line. Luckily you have a list of all of the formulas you will need...the only problem is you have no clue when to use each one! As the excellent detective you are however you are determined to fit together the pieces of the puzzle. You're everyone's last hope- help them if you can!
1 ?????WHAT DO YOU SEE?????
Search for the clues!!! No lies can be told!
1.2.1 IS IT A PROBABILITY DENSITY FUNCTION???
22.214.171.124 area under the graph = 1
126.96.36.199 calculate probabilities by integration
188.8.131.52 the graph must be above the x-axis
184.108.40.206 Mean= E(X)= (integration sign between negative infinity and infinity)xf(x)dx
220.127.116.11 variance= E(X^2) - (E(X))^2 = (integration sign between infinity abd negative infinity)x^2f(x)dx - ((integration sign between negative infinity and infinity)xf(x)dx)^2