Answer:

--- Variance
Step-by-step explanation:
Given

Solving (a): Calculate the mean.
The given data is a grouped data. So, first we calculate the class midpoint (x)
For 51 - 58.

For 59 - 66

For 67 - 74

For 75 - 82

For 83 - 90

So, the table becomes:

The mean is then calculated as:



-- approximated
Solving (b): The sample variance:
This is calculated as:

So, we have:


-- approximated
Answer:
C
Step-by-step explanation:
Solve the quadratic in answer choice C using the quadratic formula:
.
Here a=1, b=2, and c=17.
Substitute and you'll have:
Answer:
If the question states that they are not being replaced, then the answer is 1/8
If the question states that they are being replaced, then the answer is 1/9
Step-by-step explanation:
3/9 x 2/8 = 1/8
3/9 x 2/9 = 1/9
Answer:
69
Step-by-step explanation:
The sum of exterior angles is 360°, so ...
n° +131° +160° = 360°
n° = 360° -291° = 69°
n = 69
Answer: am not 100% sure but shouldn't it be all if them?
Step-by-step explanation: