Answer:
The confidence interval at this level of confidence is between 5.4455 and 12.3545.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find M as such
In which s is the standard deviation of the sample, which is also called standard error. So
The lower end of the interval is the sample mean subtracted by M. So it is 8.9 - 3.4545 = 5.4455
The upper end of the interval is the sample mean added to M. So it is 8.9 + 3.4545 = 12.3545
The confidence interval at this level of confidence is between 5.4455 and 12.3545.
The answer is 7/10 the common demontior is 10 so the numbers change to 2/10 + 5/10 witch equals 7/10
Here, Equation would be: 3.2x = 48
Where, x = 1 cm for certain distance in real
x = 48/3.2
x= 15
In short, Your Answer would be 15 Feet
[ Other Screenshot question has been answered ]
Hope this helps!
Answer:
(48.3875, 51.6125)
Step-by-step explanation:
At 99% level of significance
From the normal standard deviation table 
Considering that
± 
=50±
50±2.33(0.625)=50±1.6125=(48.3875, 51.6125)
Therefore, there’s 99% confidence that the mean lifetime of a certain brand of tires is between 48.3875 and 51.6125
If you need help the answer is 14 use long division or just subtract all depending on what the numbers are.
