Answer:
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 67
Variance = 3.85
We have to find 80% confidence interval for the population variance of the weights.
Degree of freedom = 67 - 1 = 66
Level of significance = 0.2
Chi square critical value for lower tail =
Chi square critical value for upper tail =
80% confidence interval:
Putting values, we get,
Thus, (3.13,4.91) is the required 80% confidence interval for the population variance of the weights.
Answer:
A. 162
B. 128
Step-by-step explanation:
We have wooden cubes of 2 in of side.
A. If the box is 18 x 12 x 6 in., in the base (18 x 12), we can fit 54 cubes:
As the height is 6 in, we can fit 6/2=3 layers of 54 cubes in the box, se we can fit 162 cubes:
B. If we have a box with measures 16 x 9 x 9 in., and the base is 16x9 in, we can fit (16/2)*(9/2)=8*4=32 cubes per layer.
Note that in the 9 in side we can only put 4, as we need 10 in to fit 5 cubes (we can not cut them).
In the same way, as we have 9 in of height, we can fit 4 layers of 32 cubes, so this is a total of 128 cubes: