Correct Response: B. Least-squares regression is a method that is commonly used for curve fitting data to linear and nonlinear functions. None of the other answer choices is used for curve fitting. The chi-square distribution (A) is a probability distribution commonly used for goodness-of-fit testing in statistics. The correlation coefficient (C) is used to measure the linear relationship between two variables. It is normally used when curve fitting with least-squares linear regression to express how strongly the two variables are related and whether the relationship is negative or positive. The standard deviation of a sample (D) is a statistic used in order to estimate the standard deviation of the associated population.
