Answer:
option 3 = 3.75
Step-by-step explanation:
x is 3.75
.
No hablo expanol
7(z+2)-3z=44
7z+14-3z=44
7z-3z+14=44
4z+14=44
-14 -14
4z+14-14=44-14
4z+0=30
4z=30
1/4 1/4
(4z)/4=30/4
(4/4)z=15/2
1z=15/2
z=15/2
z=15/2
Answer:
Sample mean = 7.1
Margin of error = 0.465
Step-by-step explanation:
Formula for confidence interval is;
CI = x¯ ± zE
Where;
x¯ is sample mean
z is critical value at confidence level
E is margin of error.
z for 99% Cl is 2.58
We are told the CI is 5.9 to 8.3.
Thus;
5.9 = x¯ - 2.58E - - - - (1)
8.3 = x¯ + 2.58E - - - - (2)
Add both equations together to get;
14.2 = 2x¯
x¯ = 14.2/2
x¯ = 7.1
Put 7.1 for x¯ in eq 1 to get;
5.9 = 7.1 - 2.58E
7.1 - 5.9 = 2.58E
E = 1.2/2.58
E = 0.465
