5. In this question you will consider a linear regression ofPIQ score versus brain size. {a} Dene a simple linear regression model with PIQ as the response variable and MR1 as the explanatory variable. State the model assumptions. (b) What is the estimated regession line? Interpret the values of the yintercept and slope for the model. {c} 15What percent of the variation in PIQ is explained by MRI? (d) Is the NERJ variable signicant? State this question as null and alternative hypotheses about the slope of the regression line, report the value of test statistic, the distribution of the test statistic under the null hypothesis, the p-value of the test= and state your conclusion