From the question, we know the population standard deviation, σ = 1.63, the sample standard deviation, s = 3.07, the sample mean,

and the sample size, n = 38.
The question illustrates a hypothesis chi-square test of variance.
The test statistics for a Chi-squared test of variance is given by
By the rule of

and r being 7 as it is half the diameter the answer is
If 21 is added to (+ 21) a number (x) the result (=) is 40 less than (- 40) twice the number (2x)
x + 21 = 2x - 40 Add 40 to both sides
x + 61 = 2x Subtract x from both sides
61 = x Switch the sides to make it easier to read
x = 61
Answer:
2x-7
Step-by-step explanation: