Question

find the sum of the area under the standard normal curve to the left of z = - 1.25 and the right of z = 1.25.

Answer 1

The standard normal curve is symmetric, so the area to the left of z = -1.25 is the same as that to the right of z = 1.25. Find one or the other and double your result.

To the left of 1.25: normalcdf(-1000, 1.25) = 0.1056, or 0.106. Double that; result is 0.212 (answer).