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.
Most of the time for coordinate planes, they are asking you to plot the point correctly, and to state which quadrant the point falls into.
The Quadrant points start at (+ , +) for Quadrant I, and moves clockwise. See attached picture.
Quadrant I: (+ , +)
Quadrant II: (+ , -)
Quadrant III: (- , -)
Quadrant IV: (- , +)
Remember, the point is split into two parts, in which the first one is x (which signifies the placement for the horizontal line), while the other is y (which signifies the placement for the vertical line).
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Answer:
25a-40b-10 is your answer, hope this helped :)
Step-by-step explanation:
Use this graphing app that assists you with problems like these!