Probability that an individual has​ 20-20 vision is 0.16. In a class of 90 ​students, what is the mean and standard deviation of the number with​ 20-20 vision in the​ class? Round to the nearest thousandth. A.
The mean is 90. The standard deviation is 1.1.
B.
The mean is 14.4. The standard deviation is 3.478.
C.
The mean is 90. The standard deviation is 1.2.
D.
The mean is 1.44

80° is the measure of gh

step-by-step explanation:

circle f is congruent to circle j

we have two circle with center f and j.

both circles are congruent. the radius of the circle would be equal.

see the attachment for the circle.

we are given ∠efd ≅ ∠gjh

therefore, arc (ed) = arc (gh)     (∴ circle f is congruent to circle j)

but ∠dfe=80°=arc (ed)

therefore, arc (gh) = 80°

thus, 80° is the measure of gh

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92