Question

X is distributed normally, with mean u -400, and standard deviation σ 90 A students wants to find the upper tail probability, P(X 300), and has sensibly sketched the normal distribution first. The student has shaded in the area corresponding to the probability but has not labelled their diagram completely There is no outcome of 300 on the horizontal axis, no informative label to indicate where P (X> 300) Incomplete normal distribution diagrams. Eigure 1 Figure 2 Use your knowledge of normal distributions to select the figure that has a shaded area corresponding to the upper tail probability, P (X > 300)

Answer 1

Interpretation:

The shaded area corresponding to the upper tail probability is 0.86674 using the technology. The probability that the normal random variable X is greater than 300 is approximately  $P(X>300)\approx 0.8667.$