The confidence interval is from 0.2191 to 0.2649, given by

.
The z-score we need is found by first subtracting the confidence level from 1:
1 - 0.95 = 0.05
Divide that by 2:
0.05/2 = 0.025
Subtract that from 1:
1 - 0.025 = 0.975
Look this up in the middle of a z-table (http://www.z-table.com) and we see that the z-score is 1.96.
Now our confidence interval is given by
Answer:
The solutions are given below:
Step-by-step explanation:
x(x-3)+4(x²+2)
= x²-3x+4x²+8
= x²+4x²+8-3x
= 5x²+8-3x
2(a+5)-3(a+7)
= 2a+10-3a-21
= 2a-3a+10-21
= -a-11
xy(x²yz-xy²z+xyz²)
= x³y²z-x²y³z+x²y²z²
-4(a²-2a+8)
= -4a²+8a-32
<h3>
Hope it helps !</h3>