(a) If <em>f(x)</em> is to be a proper density function, then its integral over the given support must evaulate to 1:

For the integral, substitute <em>u</em> = <em>x</em> ² and d<em>u</em> = 2<em>x</em> d<em>x</em>. Then as <em>x</em> → 0, <em>u</em> → 0; as <em>x</em> → ∞, <em>u</em> → ∞:

which reduces to
<em>c</em> / 2 (0 + 1) = 1 → <em>c</em> = 2
(b) Find the probability P(1 < <em>X </em>< 3) by integrating the density function over [1, 3] (I'll omit the steps because it's the same process as in (a)):

Answer:
8
Step-by-step explanation:
Take the total, 50.35, and subtract 19.95:
50.35 - 19.95 = 30.40
Now divide 30.40 by 3.80:
(30.4)/(3.8) = 8
Therefore, Tony bought 8 markers.
The average speed would be 53 miles per hour, hope this helped, if you need me to explain then here is the way, so all you do is divide 265 by 5 and what I did to help make it faster was split 265 into 250 and 15 so 250 divided by 5 is 50 and 15 divided by 5 is 3 so 50 + 3 = 53!
Answer:
your answer is C.
Step-by-step explanation: