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:
x+74=180
x=180-74
x=106
x=4y+22
106-22=4y
84/4=y
21=y
y=21
Step-by-step explanation:
X = 3.916
Sorry if the image is hard to read I had to smoosh it so it would fit
Answer:
I used to know how to do this
Step-by-step explanation:
I forgot tho sorry