The table below shows the probability distribution of students in a high school with 1500 students. What is the expected value for the age of a randomly chosen student? Age
13, 14, 15, 16, 18
Probability
0.01, 0.28, 0.30, 0.25,0.15,0.01

A. 15.28
B. 15.64
C. 15.34
D. 15.36

With these 5 geometry questions! pls 1.)quadrilateral abcd is inscribed in this circle.what is the measure of ∠a ? enter your answer in the box.°2.)quadrilateral abcd is inscribed in a circle.what is the measure of angle a? enter your answer in the box.m∠a= 3.)quadrilateral abcd is inscribed in this circle.what is the measure of angle b? enter your answer in the box.m∠b= °4.)quadrilateral abcd is inscribed in this circle.what is the measure of angle a? enter your answer in the box.°5.) quadrilateral abcd is inscribed in this circle.what is the measure of angle c? enter your answer in the box.°