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Complete the following table for residuals for the exponential function: f(x) = 49.3(1.47)

Hours Retweets Predicted Value Residual
1 / 65 /
2/ 90 /
3/ 162 /
4/ 224 /
5/ 337 /
6/ 466 /
7/ 780 /
8/ 1087 /

User Nidomiro
by
3.0k points

1 Answer

1 vote

Answer:

Predicted values:


\hat y_1 = 49.3 (1.47)^1 =72.471


\hat y_2 = 49.3 (1.47)^2 =106.5324


\hat y_3 = 49.3 (1.47)^3 =156.6026


\hat y_4 = 49.3 (1.47)^4 =230.2058


\hat y_5 = 49.3 (1.47)^5 =338.4025


\hat y_6 = 49.3 (1.47)^6 =497.4517


\hat y_7 = 49.3 (1.47)^7 =731.254


\hat y_8 = 49.3 (1.47)^8 =1074.943

Residuals:


e_1 = 65-72.471=-7.471


e_2 = 90-106.5324=-16.5324


e_3 = 162-156.6026 = 5.3974


e_4 = 224-230.2058 = -6.2058


e_5 = 337-338.4025 = -1.4025


e_6 = 466-497.4617 = -31.4517


e_7 = 780-731.254 = 48.7459


e_8 = 1087-1074.493 = 12.0566

Explanation:

For this case we assume the following exponential function:


\hat y_i = 49.3 (1.47)^x

Where x represent the hours and y the predicted values for each hour. We can find the estimated values like this:


\hat y_1 = 49.3 (1.47)^1 =72.471


\hat y_2 = 49.3 (1.47)^2 =106.5324


\hat y_3 = 49.3 (1.47)^3 =156.6026


\hat y_4 = 49.3 (1.47)^4 =230.2058


\hat y_5 = 49.3 (1.47)^5 =338.4025


\hat y_6 = 49.3 (1.47)^6 =497.4517


\hat y_7 = 49.3 (1.47)^7 =731.254


\hat y_8 = 49.3 (1.47)^8 =1074.943

Now we can find the residuals with this formula:


e_i = Y_i -\hat y_i

And replacing we got:


e_1 = 65-72.471=-7.471


e_2 = 90-106.5324=-16.5324


e_3 = 162-156.6026 = 5.3974


e_4 = 224-230.2058 = -6.2058


e_5 = 337-338.4025 = -1.4025


e_6 = 466-497.4617 = -31.4517


e_7 = 780-731.254 = 48.7459


e_8 = 1087-1074.493 = 12.0566

User Anthony Leach
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