Answer: D. 4167 Hertz
Step-by-step explanation:
We know that the formula to calculate frequency by using time period is given by :-
, where T is the time period.
We are given that the time period of a musical note :
Then , the frequency of the musical note is given by :-
Hence, the frequency of the musical note = 4167 Hertz
Number of aircrafts = 2939.93 + 233.517 * (years since 1990).
The predicted number of aircrafts flying in 1992 (1922 does not make sense for this equation because it returns a negative number of aircrafts) is found by pluging in the years since 1990 to 1992 = 1992 -1990 = 2 =>
number of aircrats = 2939.93 + 233.517 * (2) = 3406.96.
That is the predicted number.
The actual number is on the graph. You just go to the explanatory value 2 (years since 1990) on the horizontal axis, move straight upward until you reach the corresponding point on the graph, and read its vertical coordinate (go horizontally to the left until the vertical axis)
20 5/6 lbs.
2/3•8= 5 1/3
5 1/3+31/2= 20 5/6