A small part for an automobile rearview mirror was produced on two different punch presses. In order to describe the distribution of the weights of those parts, a random sample was selected, and each piece was weighed in grams, resulting in the following data set:

(a) Using about 10 (say, 8 to 12) classes, construct a frequency distribution.
(b) Draw a histogram of the data.
(c) Describe the shape of the distribution represented by the histogram.

3.968 3.534 4.032 3.912 3.572 4.014 3.682 3.608 3.669 3.705 4.023 3.588 3.945 3.871 3.744 3.711 3.645 3.977 3.888 3.948 3.551 3.796 3.657 3.667 3.799 4.010 3.704 3.642 3.681 3.554 4.025 4.079 3.621 3.575 3.714 4.017 4.082 3.660 3.692 3.905 3.977 3.961 3.948 3.994 3.958 3.860 3.965 3.592 3.681 3.861 3.662 3.995 4.010 3.999 3.993 4.004 3.700 4.008 3.627 3.970 3.647 3.847 3.628 3.646 3.674 3.601 4.029 3.603 3.619 4.009 4.015 3.615 3.672 3.898 3.959 3.607 3.707 3.978 3.656 4.027 3.645 3.643 3.898 3.635 3.865 3.631 3.929 3.635 3.511 3.539 3.830 3.925 3.971 3.646 3.669 3.931 4.028 3.665 3.681 3.984 3.664 3.893 3.606 3.699 3.997 3.936 3.976 3.627 3.536 3.695 3.981 3.587 3.680 3.888 3.921 3.953 3.847 3.645 4.042 3.692 3.910 3.672 3.957 3.961 3.950 3.904 3.928 3.984 3.721 3.927 3.621 4.038 4.047 3.627 3.774 3.983 3.658 4.034 3.778