Answer:
The Sample Size Need To be at least 114
Step-by-step explanation:
According to the Question,
- Given, A university dean of students wishes to estimate the average number of hours students spend doing homework per week. The standard deviation from a previous study is 6.2 hours.
The Maximum Error(E) is given as 1.5 hours and the standard deviation(σ) is 6.2 hours.
- Now, For 99% Confident the level of value α is 0.01.
α/2 = 0.01/2 ⇒ 0.005
- Thus, From The table, We get that the value of
is 2.58.
Hence, the sample size n can be found as
n = {
}²
n = {2.58 × 6.2}² / 1.5²
n = 113.72 .
So, The Sample Size Need To be at least 114.
Answer:70
Step-by-step explanation:
1
42
+
28
———
70
Answer:
Mean
Step-by-step explanation:
Mean is the average of all results.
Step 1 : Identify the formula of calculating mean
Mean = <u>Sum of all data</u>
Number of data
Step 2 : Substitute the values in the formula
Mean = <u>10 + 15 + 25 +75 + 75 + 77 + 80 +83 + 85 + 90</u>
10
Mean = <u>615</u>
10
Mean = 61.5 marks
!!
A straight angle is 180 degrees in a right angle is 90 degrees