What is the orthogonality assumption in ordinary least squares (OLS), taking LaTeX: Y\:=a+bX as the model, and the error term is LaTeX: \epsilon?

Write the equation in logarithmic form e^x=403.429

Which of the functions below could have created this graph?

Use the ratio test to determine whether ∑n=14∞n+2n! converges or diverges. (a) find the ratio of successive terms. write your answer as a fully simplified fraction. for n≥14, limn→∞∣∣∣an+1an∣∣∣=limn→∞.