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:
rate=1.28571428571.. (1.29) miles per minute, or 77.1428571429.. (77.14) mph
Step-by-step explanation:
<em>"use distance = rate time (d=rt) to find the number of miles per hour Etty must drive to go 45 miles in 35 minutes. ( remember time is written in hours?"</em>
distance=rate*time--- we know distance and time
45 mi= rate*35
rate=45/35
rate=1.28571428571 miles per minute, or 77.1428571429 mph
Answer:
A. -5/4, 9
Step-by-step explanation:
The solution is in the picture
There are two choices for each child: overweight (o) or underweight (u). So if the first child is o the next can be o or u. If the first is u the second can be o or u. This gives four possibilities. Here the first child is the letter noted first and the second is the one listed second:
OO
OU
UO
UU
There are 4 outcomes and if each is equally likely then the probability of each is 1/4. Thus the probability of UU is 1/4
The probability of one underweight and one over weight is 1/2 because in two of the outcomes listed above there is one O and one U (namely OU and UO). Since there are 4 outcomes the probability is 2/4 = 1/2
Answers:
The next two terms are 67.5 and 101.25 in that order.
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Explanation:
Divide the second term over the first to get 30/20 = 1.5
Divide the third term over the second term to get 45/30 = 1.5
The common ratio is 1.5, which means we multiply 1.5 by each term to get the next term
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fourth term = 1.5*(third term) = 1.5*45 = 67.5
fifth term = 1.5*(fourth term) = 1.5*67.5 = 101.25
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As a shortcut you can plug n = 4 and n = 5 into the function t(n) = 20*(1.5)^(n-1) to get the fourth and fifth terms respectively.
