The mean of a standard normal distribution is always = 0 with the standard deviation being equal to. Therefore a standard normal distribution is a normal distribution described with a mean of 0 and standard deviation of 1. Since a standard normal distribution is centered at the middle with equal distribution to both the left and right of the distribution. The centre point is 0, which is the mean and the standard deviation is 1 to either side of the distribution.
<span>For chess club:
y1 = 16 + 1*x where y1 = total number of members after x months
.
For film club:
y2 = 4 + 4*x where y2 = total number of members after x months.
y1 = y2 when:
16 + x = 4 + 4x
3x = 12
x = 4 months Answer: C. 4 months.</span>