Thinking about the areas of a standard normal distribution, if a z value is negative, is the area to the left of z less than 0.5000, greater than 0.5000 or equal to 0.5000?
It will be less than 0.5000 This is because the total area under the normal distribution curve = 1. This means the area to the left of the midpoint is exactly 0.5000, if the z value is negative it is slightly pushed to the left of the midpoint. This decreases the area on the left.