Simple interest formula
Interest = Pit = $50
P=principal (initial investment)
i=annual interest rate = 0.04
t=time in years = 6 months = 0.5 years
Substitute values,
$50 = P*0.04*0.5
Solve for P
P=$50/(0.04*0.5)=$2500
The regression equation for the data given is y= -8.57 -2.31x
Step-by-step explanation:
The first step is to form a table as shown below;
x y xy x² y²
1 4 4 1 16
2 1 2 4 1
3 5 15 9 25
4 10 40 16 100
5 16 80 25 256
6 19 114 36 361
7 15 105 49 225
28 60 360 140 984 ------sum
A linear regression equation is in the form of y=A+Bx
where ;
x=independent variable
y=dependent variable
n=sample size/number of data points
A and B are constants that describe the y-intercept and the slope of the line
Calculating the constants;
A=(∑y)(∑x²) - (∑x)(∑xy) / n(∑x²) - (∑x)²
A=(60)(140) - (28)(360) / 7(140)-(28)²
A=8400 - 10080 /980-784
A= -1680/196
A= - 8.57
B= n(∑xy) - (∑x) (∑y) / n(∑x²) - (∑x)²
B= 7(360)-(28)(60) / 7(60) - (28)²
B=2520 - 1680 /420-784
B=840/-364
B= -2.31
y=A+Bx
y= -8.57 -2.31x
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Regression equation :brainly.com/question/12280902
Keywords : equations, regression line, data
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Okay I think there has been a transcription issue here because it appears to me there are two answers. However I can spot where some brackets might be missing, bear with me on that.
A direct variation, a phrase I haven't heard before, sounds a lot like a direct proportion, something I am familiar with. A direct proportion satisfies two criteria:
The gradient of the function is constant s the independent variable (x) varies
The graph passes through the origin. That is to say when x = 0, y = 0.
Looking at these graphs, two can immediately be ruled out. Clearly A and D pass through the origin, and the gradient is constant because they are linear functions, so they are direct variations.
This leaves B and C. The graph of 1/x does not have a constant gradient, so any stretch of this graph (to y = k/x for some constant k) will similarly not be direct variation. Indeed there is a special name for this function, inverse proportion/variation. It appears both B and C are inverse proportion, however if I interpret B as y = (2/5)x instead, it is actually linear.
This leaves C as the odd one out.
I hope this helps you :)
