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
I think the group 2 survey is likely to be biased towards people who are not too keen on zoos since all the values are small.
From group 1 and 3 the mean number of visits are
(4 + 10 + 6 + 3 + 8 + 7 + 9 + 3 + 4 + 7) / 10
= 61/10
mean = 6
Answer:
um D
Step-by-step explanation:
2.3 +.4=18 yeP THATS THE ANSWER ._.
