Answer: a. 90°
Step-by-step explanation:
We know that the in a circle, the measure of an inscribed angle is half the measure of the central angle with the same intercepted arc.
In the problem∠XYZ is the inscribed angle
∠XYZ=
⇒ ∠XYZ=
Since XZ is a diameter of the circle which is a line segment, thus ∠XZ=180°
∴ ∠XYZ=
∴ ∠XYZ=
Therefore, a. 90° is the measure of ∠XYZ.
The number of standard deviations from the mean for a man 72 inches tall is
Z = (72 -69.3)/2.8 ≈ 0.964
To find the z-score for a weight of 196 oz., use

A table for the cumulative distribution function for the normal distribution (see picture) gives the area 0.9772 BELOW the z-score z = 2. Carl is wondering about the percentage of boxes with weights ABOVE z = 2. The total area under the normal curve is 1, so subtract .9772 from 1.0000.
1.0000 - .9772 = 0.0228, so about 2.3% of the boxes will weigh more than 196 oz.