Answer:

Step-by-step explanation:
we know that
The<u><em> Intersecting Secant-Tangent Theorem,</em></u> states that : If a tangent segment and a secant segment are drawn to a circle from an exterior point, then the square of the measure of the tangent segment is equal to the product of the measures of the secant segment and its external secant segment.
so
In this problem

we have

substitute the given values

solve for x

therefore

He pays $780 for the television set.
1200*.35=420
1200-420=780
1/(3b)=4/5 multiply both sides by 5
5/(3b)=4 multiply both sides by 3b
5=12b divide both sides by 12
b=5/12 (not sure why you don't have that as an option in your answers, perhaps I misunderstood your description of the original equation...)
Answer:
2.25
Step-by-step explanation:
The total frequency is:
20 + 12 + 6 + 2 = 40
Calculate the probability of each score:
P(X=3) = 20/40 = 0.50
P(X=2) = 12/40 = 0.30
P(X=1) = 6/40 = 0.15
P(X=0) = 2/40 = 0.05
So the expected value is:
E = (3)(0.50) + (2)(0.30) + (1)(0.15) + (0)(0.05)
E = 2.25