Class interval should always be a whole number and yet in this case we have a decimal number. The solution to this problem is to round off to the nearest whole number. In this example, 2.8 gets rounded up to 3. So now our class width will be 3; meaning that we group the above data into groups of 3 as in the table below.
Skeletons come in a number of forms, each suited for a particular set of lifestyles and environments. Skeletons can be rigid, semirigid, or soft. They can also be external or internal. Vertebrates have internal skeletons, called bony skeletons, which consist mainly of calcified bone tissue. Most invertebrates, such as insects, spiders, and crustaceans, have outer skeletons called exoskeletons.
Human skeleton can be divided into two divisions. Axial Skeleton: Axial skeleton forms the axis of human body. It consists of Skull, vertebral column and thoracic cage. 1  Skull: Skull is that part of human skeleton that forms the bony framework of the head.2  It consists of 22 different bones that are divided into two groups: bones of cranium and bones of face.keletal system is the system of bones, associated cartilages and joints of human body. Together these structures form the human skeleton. Skeleton can be defined as the hard framework of human body around which the entire body is built.