Henry needs to give informal proof of the formula for the circumference of a circle. He first constructs a circle, with center O, and labels a point on the circle as P.
He draws a radius from O to P.
He then uses point P as the center to construct a new circle.
He draws two line segments, each formed by joining point O with the points of intersection of the two circles.
Which of these is a plausible next step in Henry's proof process?

Construct another circle with a doubled radius.

Construct a rectangle that circumscribes the original circle.

Construct an octagon that circumscribes the original circle.

Construct a hexagon inscribed in the original circle.

I'm confused on this could anyone me and show me what i need to do to solve it.

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?

How is the interquartile range calculated?