Answer:
the answer is attached to the picture
Answer:
-6.95 x 10^10
Step-by-step explanation:
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
Answer:
No, no, yes, no
Step-by-step explanation:
The first one is not random. He is sampling only the earliest gym goers.
The second one is not random. He is sampling only from one zip code.
The third one is random. He is using a random number generator.
The fourth one is not random. He is sampling only volunteers.
