Obtain the following R output, treating IQ as the response variable: (i) scatter plot (ii) standardised residual plot (iii) distribution of residuals

Could you please help me with the R code for (iii). I have done the histogram but there is gap between the bins and look bit weird .

What statistical model is assumed in your regression analysis?

As far as possible, assess the extent to which the model is appropriate to the data.?

IQ BrainV 132 816.932 132 951.545 90 928.799 136 991.305 90 854.258 129 833.868 120 856.472 100 878.897 71 865.363 132 852.244 112 808.02 129 790.619 86 831.772 90 798.612 83 793.549 126 866.662 126 857.782 90 834.344 129 948.066 86 893.983