The formula for the confidence interval is given by
Sample mean + z*[σ/√n], and
Sample mean - z*[σ/√n]
We have:
Sample mean = 23.95
n = 40
σ = 2.55
z* for 99% confidence = 2.58
Substitute these values into the formula, we have
23.95 + (2.58)(2.55÷√40) = 24.99
23.95 - (2.58)(2.55÷√40) = 22.91
So the lower interval is 22.91 and the highest interval is 24.99
Answer:
B
Step-by-step explanation:
I added all of then and then subtracted 47 from the 50.
Answer: 95.45 %
Step-by-step explanation:
Given : The distribution is bell shaped , then the distribution must be normal distribution.
Mean : 
Standard deviation :
The formula to calculate the z-score :-
For x = 13
For x = 19
The p-value = 
In percent, 
Hence, the percentage of data lie between 13 and 19 = 95.45 %
Step-by-step explanation:
Since angles in the same segment are equal, Angle ABC (x) = Angle AOC.
Since Angles AOC and COD are supplementary, Angle AOC = 180° - 130° = 50°
Therefore x = 50°.
