The confidence interval formula is computed by:
Xbar ± Z s/ sqrt (n)
Where:
Xbar is the mean
Z is the z value
S is the standard deviation
N is the number of samples
So our given are:
90% confidence interval with a z value of 1.645
Sample size 40, 45
Mean 180, 179
Standard deviation 2, 4
So plugging that information in the data will give us a
confidence interval:
For 1:
Xbar ± Z s/ sqrt (n)
= 180 ± 1.645 (2 / sqrt (40))
= 180 ± 1.645 (0.316227766)
= 180 ± 0.520194675
= 179.48, 180.52
For 2:
Xbar ± Z s/ sqrt (n)
= 179 ± 1.645 (4 / sqrt (45))
<span>= 179 ± 1.645 (0.596284794)</span>
therefore, the answer is letter b
600 x 40 I think the new dimetions will be
First, we know L and W are the same number. The in the end the Length is 6 more, therefore we add 6. The equations begins as so
2x+6=27
-6
2x=21
/2
x=10.5
+6
Therefore the Width =10.5 M
The Length = 16.5 M
Move the 14 over and get
5x = 2
divide by 5
x = 2/5
Opposite
additive inverse
