An endocrinologist was interested in exploring the relationship between the level of a steroid (Y) and age (X) in healthy subjects whose ages ranged from 8 to 25 years. She collected a sample of 27 healthy subject in this age range. The data is located in the file problem01.txt, where the first column represents X = age and the second column represents Y = steroid level. For all R programming, print input and output codes and values, data to be used is below. (Create a quadratic regression in R. Write down the fitted equation, multiple R2, and the p-value for β1 from the summary()output.

Yi =β0 + β1Xi + β2Xi2 + εi