Answer:
13
Step-by-step explanation:
We need the circumference and area of the circle equations:
c = 2*pi*r
a = pi*r^2
lets find the radius from the first equation:
r = c/2*pi
r = 157/(2*3.14)
r = 24.99 ft
now lets calculate the area:
a = pi*r^2
a = 3.14*(24.99)^2
a = 1960.93 ft^2
Now we need to divide the total area by the rate at which Chris paints, and that gives us the time needed:
time = <span>1960.93/400
time = 4.9 hours
that would be 5 hours rounded to the nearest hour</span>
Answer:
Option a
Step-by-step explanation:
Given two normal distribution samples
I group has 106 as mean and 8.5 as std deviation with sample size = 60
II group has 121 as mean and 6.3 as std deviation with sample size =38
We find mean difference =-15
For margin of error finding, we have to find the combined std error for the difference
Variance of difference = Sum of variances
STd error for difference = 1.50
Hence for 99% margin of error =2.58(1.50)
= 3.87
To turn a number to a percent, multiply by 100 = 600%
