About % of the area under the curve of the standard normal distribution is between z = − 1.686 and z = 1.686 (or within 1.686 standard deviations of the mean).

Question

About *Blank* % of the area under the curve of the standard normal distribution is between  and  (or within 1.686 standard deviations of the mean).

Answer 1

P(-1.686 < z < 1.686) = P(z < 1.686) - P(z < -1.686). Look up probabilities in standard normal probability table.