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:
30.4 miles
Step-by-step explanations:
Please refer to the attached image for explanations
Tan x=opposite/adjacent
cot x=adjacent/opposite
so you need to inverse the fraction
tan x=.78 as a fraction is 78/100
-> inversed= 100/78=1.28=cot x
so it is the second option
Answer:
D. 1/3
Step-by-step explanation:
