The systolic blood pressure of a group of 18-year-old women is normally distributed with a mean of 112 mmhg and a standard deviation of 11 mmhg. what percentage of 18-year-old women in this group have a systolic blood pressure that lies within 3 standard deviations to either side of the mean?

By the empirical rule, 99.7 percent of all values in a normal distribution lie within 3 standard deviations of the mean. Since the population is normally distributed, the percentage that lies within 3 standard deviations of the mean is 99.7 percent.

Alternatively, you can use a z-score table to look up the area between -infinity and -3 to get the percentage that lies below 3 standard deviations below the mean, and the rest of the calculations should be trivial.

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.  

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]