Answer: a) 84 and b ) 2084
Step-by-step explanation:
Given : Sample standard deviation : s= $22.82
(Population standard deviation is unknown ) , so we use t-test.
Critical value or the 95% confidence intervals :
Formula to find the sample size :

a) E = 5


i.e. Required sample size : n= 84
b) E = 1


i.e. Required sample size : n= 2084
First, we need to transform the equation into its standard form (x - h)²=4p(y - k).
Using completing the square method:
y = -14x² - 2x - 2
y = -14(x² + 2x/14) - 2
y = -14(x² + 2x/14 + (2/28)²) -2 + (2/28)²
y = -14(x + 1/14)² - 391/196
-1/14(y + 391/196) = (x + 1/14)²
This is a vertical parabola and its focus <span>(h, k + p) is (-1/14, -391/196 + 1/56) = (-1/14, -775/392).
Or (-0.071,-1.977).</span>
Answer:

Step-by-step explanation:

Hope this helps!