Notice that in
[link] the slope is positive and in
[link] the slope is negative. Do you notice any difference in the two lines shown in
[link] (a) and
[link] (b)?
We ‘read’ a line from left to right just like we read words in English. As you read from left to right, the line in
[link] (a) is going up; it has
positive slope . The line in
[link] (b) is going down; it has
negative slope .
Positive and negative slopes
Use a geoboard to model a line with slope
.
Solution
To model a line on a geoboard, we need the rise and the run.
So, the rise is 1 and the run is 2.
Start at a peg in the lower left of the geoboard.
Stretch the rubber band up 1 unit, and then right 2 units.
The hypotenuse of the right triangle formed by the rubber band represents a line whose slope is
.
Now, we’ll look at some graphs on the
-coordinate plane and see how to find their slopes. The method will be very similar to what we just modeled on our geoboards.
To find the slope, we must count out the rise and the run. But where do we start?
We locate two points on the line whose coordinates are integers. We then start with the point on the left and sketch a right triangle, so we can count the rise and run.
How to use
To find the slope of a line from its graph
Step 1: Find the mean. To find the mean, add up all the scores, then divide them by the number of scores. ...
Step 2: Find each score's deviation from the mean. ...
Step 3: Square each deviation from the mean. ...
Step 4: Find the sum of squares. ...
Step 5: Divide the sum of squares by n – 1 or N.
The sample of 16 students is taken. The average age in the sample was 22 years with astandard deviation of 6 years. Construct a 95% confidence interval for the age of the population.
Bhartdarshan' is an internet-based travel agency wherein customer can see videos of the cities they plant to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400
a. what is the probability of getting more than 12,000 hits?
b. what is the probability of getting fewer than 9,000 hits?
Bhartdarshan'is an internet-based travel agency wherein customer can see videos of the cities they plan to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400.
a. What is the probability of getting more than 12,000 hits