The masses of Fuji apples are normally distributed with a mean of 163 g and a standard deviation of 6.83 g. When Fuji apples are picked, they are classified as small, medium, large or extra large depending on their mass. Large apples have a mass of between 172 g and 183 g.

sketch of normal curve with shaded region to the right of the mean and correct values

$0.0921(0.0920950\ldots)$

EITHER $(P(x<172))$ $0.906200\ldots$ $(0.906200\ldots-0.68)$ $0.226200\ldots$

OR

$(P(163<x<172))$ $0.406200\ldots$ $0.5-(0.68-0.406200\ldots)$ OR $0.5+(0.68-0.406200\ldots)$ $0.226200\ldots$ OR 0.773799 ...

OR

Note: Award $A1$ for a normal distribution curve with a vertical line on each side of the mean and a correct probability of either 0.406 or 0.274 or 0.906 shown, A1 for a probability of 0.226 seen.

THEN

$(k=) 158$ g $(157.867\ldots$ g)