Write the Equation
Write the equation with a rate of change of ⅓ and a y-intercept at (0, -4)
y=1/3x - 4
The initial value is also called what?
y-intercept
The number of members in a club (Y) that doubles in size every (x) years
Linear
What type of correlation would you expect from: a student’s score on a math test, students high school grades?
positive
Correlation or causation:
As the number of high schools increases, the number of enrolled students goes up?
Correlation (just because there are more schools, doesn’t mean there are more students to fill them)
write the equation for a line with an initial value of 5 and the average rate of change is -1
Y=-1x +5
Or
Y= -x+5
The rate of change is also called what?
slope
The value of an investment (y) that began with $500 and earns 4.25% each year
exponential
What type of correlation would you expect between the number of minutes a candle burns and the height of the candle?
Negative
Correlation or causation:
As the number of weddings increase, the number of marriage licenses increases
Causation (actually legally causes it to happen)
Write an equation for the situation:
A plant started at 1 inch tall and grew .25 inches each week
y=o.25x + 1
or
y=1/4x + 1
What is the meaning of the slope in the following situation:
A cell phone company offers a plan that is represented by the linear model T(c)=30 + 0.1c
Where t is the total cost and c is the number of minutes used?
a. Cost of plan with c minutes used
b. Cost of the plan with no minutes used
c. Month cost for the phone
d. Cost per minute
d. cost per minute
A student receives $50 each year for his birthday.
linear
What does the correlation coefficient of -0.975 indicate about the type of correlation?
Strong or weak?
Negative or positive?
Strong Negative
Correlation or causation:
The amount of time a candle burns and the height of the candle after burning
Causation (a candles can only get smaller when it burns)
write an equation for the situation:
Amanda has $550 in her bank account and earns $30 each week for chores.
Y= 30x + 550
In the table below, residents were surveyed on how many weeks they have had service at their complex. What is the meaning of the y-intercept below:
Number of weeks: 0, 1, 2
Number of residents: 8, 15, 19
a. The rate of change of residents
b. The maximum number of residents
c. The initial number of residents
d. Initial rate at which residents received meters
c. the initial number of residents
The total cost (y) to purchase (x) number of tickets to a sporting event if a 20% service charge is added to the cost of each ticket
exponential
What does the correlation coefficient of 0.632 indicate about the type of correlation?
Strong or weak?
Negative or positive?
Weak Positive
Correlation or causation:
The older you are, the taller you are
Correlation(some of you are taller than me and Mr. Willey or your parents)
write an equation for the situation:
Frank starts his weight loss journey at 350 pounds and loses 7.5 pounds every week.
Y= -7.5x + 350
or
y= 350 - 7.5x
In the table below, numbers of hours spent online and students current math grades are shown, where the more hours spent online, the lower the math grade. What is the best description of the y-intercept for the equation:
number of hours online: 8, 12, 15
current math grade: 82, 78, 73
a. Number of hours spent online if a students grade is 0
b. The average change in the grade per hour spent online
c. The grade a student should expect with no time spent online
d. The point at which a students grade is the lowest
c. the grade a student should expect with no time spent online
The height (y) of a ball at (x) seconds after it was hit off a tee at an initial velocity of 60 feet per second.
quadratic
Between what two numbers will the correlation coefficient be between?
-1 and +1
correlation or causation:
The less calories consumed, the more weight you lose
Correlation (less calories can cause the opposite effect, working out usually helps burn more fat and calories but not the same for everyone)