Answer: b. 0.98
Step-by-step explanation:
The formula to find the maximum error of the estimated mean :
(1)
, where
= standard deviation
n= Sample size
z* = Critical z-value.
As per given , we have

n=100
Critical value for 95% confidence interval = z*=1.96
Put these values in the formula (1), we get


Hence, the maximum error of the estimated mean quality for a 95% level of confidence is 0.98.
Therefore , the correct answer is b. 0.98 .
Answer:
<h2>0</h2>
Step-by-step explanation:




Answer:
0.45
Step-by-step explanation:
Divide 9 by 20.
36 questions-----3 minutes
x questiones-----1 minutes
x=(1*36)/3
x=36/3
x=12 questions
B.
Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.