Answer:
so sorry
Step-by-step explanation:
In cylindrical coordinates, we have
, so that

correspond to the upper and lower halves of a sphere with radius
. In spherical coordinates, this sphere is
.
means our region is between two cylinders with radius 1 and
. In spherical coordinates, the inner cylinder has equation

This cylinder meets the sphere when

which occurs at

where
. Then
.
The volume element transforms to

Putting everything together, we have

Jim is correct because the ratios need to compare with the total amount of people surveyed. 55, 80, and 65 are numbers that don't fit in and don't tell the overall ratio. You can tell this by writing it as a fraction.
Ex: 35:100 = 35/100. This literally means 35 out of 100 people exercise in the morning.
Hope this helps! If you have any questions, just ask!
Answer:
See it in the pic.
Step-by-step explanation:
See it in the pic.
Answer:
Guo Qi requires 75 days to watch videos on Khan Academy.
Step-by-step explanation:
We are given the following in the question:
Number of videos watched by Guo Qi each day = 15
Average length of each video = 8 minutes
Total minutes of video = 9000 minutes
Total number of videos to be watched =

Guo Qi needs to watch 1125 videos.
Number of days required =

Guo Qi requires 75 days to watch videos on Khan Academy.