8 junior high classes will be chosen to participate in a school improvement survey. there are 21 junior high classes in the scho
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Answer:
Here's what I get.
Step-by-step explanation:
Part A. Equation in standard form
The question is asking you to find the equation of a straight line that passes through two points
Let x = the number of days
and y = the cost
Then the coordinates of the two points are (2,225) and (5,480).
(i) Calculate the slope of the line
In other words, the daily rental is $85/day.
(ii) Calculate the y-intercept
(iii) Write the equation for the line
y = 85x + 55
That is, the cost is $55 plus $85/day
Part B. Equation in function notation
Replace y with ƒ(x)
ƒ(x) = 85x + 55
Part C. Graphing
Let's say you want to plot a graph of the rental cost for up to ten days.
(i) Calculate two points on the graph.
When x = 0, y = 85; when x = 10, y = 905.
(ii) Scale your axes
A good number of intervals is about ten.
Your x-axis should have tick marks at 1-day intervals.
Your largest y-value is 905. Ten intervals would make about $90/interval. However, you should round that up to $100/interval for easy interpolation.
Your y-axis will run from 0 to $1000 in $100 intervals.
Plot your two points and draw a straight line through them.
(iii) Axis labels
x represents the number of days, so the label on the x-axis could be "No. of days."
y represents the cost of renting the boat, so the label on the y-axis could be "Rental cost."
Your graph should resemble the one below.
