If a fund's returns follow a normal distribution, then approximately 68% of the time they will fall within one standard deviation of the mean return for the fund, and 95% of the time within two standard deviations.
Mammals are a particular class of animal. What makes an animal a mammal are several things. First, they must have glands that give milk.This is to feed their babies. Second, they are warm-blooded.Third, all mammals have fur or hair. Humans are mammals and so are dogs, whales, elephants, and horses.hat makes an animal a mammal are several things. First, they must have glands that give milk. This is to feed their babies. Second, they are warm-blooded. Third, all mammals have fur or hair. Humans are mammals and so are dogs, whales, elephants, and horses.
Instead, scientists look to features of skeletons that are preserved in fossils such as three bones in the ear and a unique jaw joint.Ancestors of mammals first To know when mammals appeared, we need to know what characteristics make an animal a mammal. There are a few we think of right away â mammary glands to produce milk, warm-blooded, hair or fur, and birth of live young. Most of these features, however, are lost in fossils because they are made of soft tissue that decomposes.