Answer:
Step-by-step explanation:
Given that each of 165 newly manufactured items is examined and the number of scratches per item is recorded (the items are supposed to be free of scratches), yielding the following data
x freq x*f x^2*f
0 25 0 0
1 34 34 34
2 37 74 148
3 29 87 261
4 19 76 304
5 8 40 200
6 8 48 288
7 5 35 245
165 394 1480
Mean 2.387878788 8.96969697
Variance 3.267731864
We get E(x) = 2.388 and hence unbiased estimator of mu is 2.388
b) Variance = 3.268
Answer:
C) 171.40
Step-by-step explanation:
The formula to find the volume of a rectangular prism is:
l x w x h = V
Substitute values:
4.2 x 5.3 x 7.7 = 171.40
So, there's your answer!
The mean will be calculates as follows; from the formula of z-score we shall have:
z=(x-μ)/σ
the z-score associated with 0.5% is 0
thus
0=
(8-μ)/0.4=0
solving for x we get:
μ=9
Answer: μ=9
