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.
Like the frog, the rat also has an endoskeleton with 223 bones that are distributed into the axial skeleton and the appendicular skeleton. The rat is also the only organism that we have studied that has a ribcage that covers most of its body.he frog's skeletal system is very different from the humans even though they both have a endoskeletons. The endoskeleton forms a supporting framework for the body, it can be well know as an appendicular skeleton and an axial skeleton. Appendicular skeleton consists of the pectoral, pelvic, and the limb bones.