How can you measure the quality of the linear approximation offered by the above model? What is meant by R 2 = 1 and R 2 = 0?

Suppose I have run the simple linear reggression model through R code based on Data file(name is DATA) which has 30 line data. Now I need plot and run the simple linear reggression model through R code based on same Data file with only 1 to 20 lines data. If I wrote the code : Data2=[1:20], then use plot(), lm(), fit() commands. cant work it How to write the R code for the second simple linear reggression mode ? thanks for your help.

5_d. Please give step by step solution. Please do part d.

The speed of sound in a particular medium is f (T) = 344.51/1+ T meters/second 273.15 where T'is the temperature in degrees Celsius. Find a linear function that approximates the speed of sound for temperatures near O°C. Specifically, fill in the missing numbers below for the local linearization of f at T = 0. Round your answers to three decimal places. f(T) = •T meters/second