Final answer:
To find P(Z ≥ -0.99) for a standard normal distribution, you look up the area to the left of z=-0.99 in a z-table or use a calculator and subtract it from 1, since the total area to the right of z=0 is 0.5.
Step-by-step explanation:
To find the probability P(Z ≥ -0.99) for a random variable Z that follows a standard normal distribution, we need to calculate the area under the normal curve to the right of the z-score -0.99. Since standard normal distribution tables, also known as z-tables, typically provide the area to the left of a given z-score, we can use this property to find our answer.
We look up the z-score of -0.99 in a z-table or use calculator commands like invNorm(0.975,0,1) to find the corresponding area to the left, which is 0.8385 (this value may vary slightly depending on the source of the z-table or accuracy of the calculator). The total area under the curve to the left of z=0 is 0.5, as the curve is symmetric around zero. Therefore, to find P(Z ≥ -0.99), we subtract the area to the left of -0.99 from the total area on the right side of the curve, which is 1.
Thus, P(Z ≥ -0.99) = 1 - 0.1615 = 0.8385 (again, this can differ slightly). This result gives us the area under the curve to the right of -0.99, which corresponds to the probability that Z is greater than or equal to -0.99.