Answer:
Ok what's your question? cna you include the graph?
2.5*7 = 17.5. If it's easier for you, multiply 2.5 by 5 then add 2.5*2.
Answer:
Value of k is
Step-by-step explanation:
We are given the following information in the question:

where x is the time elapses between the end of the hour and the end of the lecture.
We have to find the values of k.
Since, f(x) is the pdf, then,
![\displaystyle\int^\infty_{-\infty} f(x) = 1\\\\\displaystyle\int^2_{0} f(x) = 1\\\\\displaystyle\int^2_{0} kx^2 = 1\\\\k\bigg[\frac{x^3}{3}\bigg]^2_0 = 1\\\\k\times \frac{8}{3} = 1\\\\k = \frac{3}{8}](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Cint%5E%5Cinfty_%7B-%5Cinfty%7D%20f%28x%29%20%3D%201%5C%5C%5C%5C%5Cdisplaystyle%5Cint%5E2_%7B0%7D%20f%28x%29%20%3D%201%5C%5C%5C%5C%5Cdisplaystyle%5Cint%5E2_%7B0%7D%20kx%5E2%20%3D%201%5C%5C%5C%5Ck%5Cbigg%5B%5Cfrac%7Bx%5E3%7D%7B3%7D%5Cbigg%5D%5E2_0%20%3D%201%5C%5C%5C%5Ck%5Ctimes%20%5Cfrac%7B8%7D%7B3%7D%20%3D%201%5C%5C%5C%5Ck%20%3D%20%5Cfrac%7B3%7D%7B8%7D)
Hence, value of k is 
To round 389,422 to the ten thousand, you need to go to the second number which is 8 and round it to the right. To the right of 8 is 9 so if a number is more than 5 you round 8 to 9. Then all the numbers after 8 turn into zeros
So... your answer is:
390,000
Hope I helped! ♥