The circumference equals diameter x pie which equals:
17x3.14=53.38cm.
Answer:
I think the working is actually unnecessary because of (x-c)=0 and if x is 5 (5-c)=0 c would be 5
D. All students in each grade. It can't be A since the survey is for the students, it defeats the purpose. It can't be B and C since those are too biased. Basing the student population on one factor like gender and sports is not logical in the context of this survey.
Answer: 74.8%
This answer is approximate.
The value is rounded to the nearest tenth of a percent.
==========================================
Explanation:
Let,
X = area of the larger circle
Y = area of the smaller circle
Z = area of the shaded region = X - Y
The goal is to compute the ratio Z/X to get the answer we want
Let's find area of the larger circle
Area of circle = pi*(radius)^2
A = pi*r^2
X = pi*8.01^2
X = 64.1601pi
This is the exact area in terms of pi
Now repeat for the smaller circle
A = pi*r^2
Y = pi*4.02^2
Y = 16.1604pi
Subtract those results to find the value of Z
Z = X-Y
Z = 64.1601pi-16.1604pi
Z = 47.9997pi
This is the exact area of the red donut region
Divide Z over X to get the probability of landing in the red region
Z/X = (47.9997pi)/(64.1601pi)
Z/X = (47.9997)/(64.1601) <--- note how the pi terms cancel
Z/X = 0.74812 which is approximate
Convert to a percent
Move the decimal point 2 spots to the right
0.74812 ---> 74.812%
Then round this to one decimal place
74.812% ---> 74.8%
Answer:
I think 3 ,4 ,and 5 are to only correct ones
