Question 1(Multiple Choice Worth 1 points)
(03.03 LC)
The number of members, f(x), in a baseball club increased by 45% every year over a period of x years. The function below shows the relationship between f(x) and x:
f(x) = 25(1.45)x
Which of the following graphs best represents the function?
a. graph of exponential function going up from left to right through the point approximately 0 comma 1 and 5 tenths and approximately 4 tenths comma 5
b. graph of exponential function going up from left to right in quadrant 1 through the point 0, 0 and continuing toward infinity
c. graph of exponential function going up from left to right through the point approximately 0 comma 1 and approximately 2 comma 2
d. graph of exponential function going up from left to right through the point 0 comma 25 and approximately 3 comma 75
5 answers
x 2 3 4 5
f(x) 9 3 1 one-third
Graph f(x) and identify the y-intercept.
a. 9
b. 15
c. 36
d. 81
The graph of the exponential function would start at (2, 9) and decrease rapidly as x increases. However, we are not given specific values for the y-coordinate when x is not an integer, so we cannot accurately draw the graph beyond the given points.
To find the y-intercept, we can determine the value of f(x) when x = 0.
Using the given points, we observe that f(3) = 3 and f(4) = 1.
Since the function is continuous, we can assume that the value of f(x) decreases steadily from 3 to 1 as x increases.
Therefore, we can estimate that f(2) is likely to be greater than 9, the y-coordinate at x = 3.
From the given answer choices, the only option that fits this estimation is (c) 36.
Therefore, the y-intercept is 36.
x 1 2 3 4 5
f(x) 243 81 27 9 3
Compute the average rate of change of f(x) from x = 1 to x = 4, and describe what it represents.
a. −78 contestants per round, and it represents the number of contestants who will reach the final round
b. −234 contestants per round, and it represents the number of contestants who will reach the final round
c. −234 contestants per round, and it represents the average rate at which the number of contestants changed from the first round to the fourth round
d. −78 contestants per round, and it represents the average rate at which the number of contestants changed from the first round to the fourth round
Average Rate of Change = (f(4) - f(1))/(4 - 1)
From the given table, we can determine that f(1) = 243 and f(4) = 9.
Substituting these values into the formula, we get:
Average Rate of Change = (9 - 243)/(4 - 1)
= (-234)/3
= -78
Therefore, the average rate of change of f(x) from x = 1 to x = 4 is -78 contestants per round.
Now, let's consider the last part of the question: what does this average rate of change represent?
Since we are computing the average rate of change from the first round to the fourth round, the -78 contestants per round represents the average rate at which the number of contestants changed from the first round to the fourth round.
Therefore, the correct answer is (d) -78 contestants per round, and it represents the average rate at which the number of contestants changed from the first round to the fourth round.