There are 375 books sold at sid's bookstore. the table below summarizes these books by genre. this info is presented in circle graph. find the central angle measure for self slice in graph. mystery 99, romance 81, self 90, cooking 57, biography 48.

When you plot the data in a pie graph, it looks like that shown in the picture. A circle is formed when you draw a point and connect it from end to end forming a complete revolution. One revolution equals 360°. Therefore, each piece of pie for each type of book is a fraction of one revolution. The fraction can be determined by dividing the number for a specific type of book to the total number of books. Specifically, the fraction for the Self Help slice would be 90/375 which is equal to 0.24 or 24%. Then, 24% of 360 is 86.4. Therefore, the central angle formed by the Self Help slice is 86.4°.