Find the probability that based on the normal distribution.
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces.
What proportion of items will weigh between 6.4 and 8.9 ounces?
i) 0.1145
ii) 0.2881
iii) 0.1736
iv) 0.4617