Let us say that the samples for fifty movies is 1 and
samples for thirty five is 2. To solve the test statistic z, we can use the
formula:
z = (p1 – p2) / sqrt [p (1 – p) (1 / n1 + 1 / n2)]
Where,
p1 = is the proportion for sample 1 = 0.36
p2 = is the proportion for sample 2 = 0.23
n1 = number of samples = 50
n2 = number of samples = 35
while p can be calculated using the formula:
p = [p1 * n1 / (n1 + n2)] + [p2 * n2 / (n1 + n2)]
p = [0.36 * 50 / (50 + 35)] + [0.23 * 35 / (50 + 35)]
p = 0.211764705 + 0.094705882
p = 0.306470587
Going back for the calculation of z:
z = (0.36 – 0.23) / sqrt [0.306 (1 – 0.306) (1 / 50 + 1 /
35)]
z = 1.279
Therefore the nearest answer is:
z = 1.29
S(-6, 4)
If you plot on a simple graph you will find the other end point S there
That is a scale factor of 1.
