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There were two widely divergent influences on the early development of statistical methods.Statistics had a mother who was dedicated to keeping orderly records of governmental units （state and statistics come from the same Latin root，status）and a gentlemanly gambling father who relied on mathematics to increase his skill at playing the odds in games of chance.The influence of the mother on the offspring，statistics，is represented by counting，measuring，describing，tabulating，ordering，and the taking of censuses——all of which led to modem descriptive statistics.From the influence of the father came modem inferential statistics，which is based squarely on theories of probability.
Descriptive statistics involves tabulating，depicting，and describing collections of data.These data may be either quantitative，such as measures of height，intelligence，or grade level——variables that are characterized by an underlying continuum or the data may represent qualitative variable，such as sex，college major，or personality type.
Large masses of data must generally undergo a process of summarization or reduction before they are comprehensible.Descriptive statistics is tool for describing or summarizing or reducing to comprehensible form.the properties of an otherwise unwieldy mass of data.
Inferential statistics is a formalized body of methods for solving another class of problems that present great difficulties for the unaided human mind.This general class of problems characteristically involves attempts to make predictions using a sample of observations.For example，a school superintendent wishes to determine the proportion of children in a large school system who come to school without breakfast，have been vaccinated for flu，or whatever.Having a little knowledge of statistics，the superintendent would know that it is unnecessary and inefficient to question each child；the proportion for the entire district could be estimated fairly accurately from a sample of as few as 100children.Thus，the purpose of inferential statistics is to predict or estimate characteristics of a population from knowledge of the characteristics of only a sample of the population.

Love can’t conquer all.So，before couples tie the knot，they should know what they’re getting into.The taboo against couples living together before marriage is decreasing，and more and more people axe saying’I do’after they’ve spent months，or even years，living together.
As much as a person loves another，he or she never really knows what happens behind closed doors unless he or she is standing on the other side.While some people view living together before marriage as immoral，couples are actually expanding the boundaries of their relationship by moving in together.For example，the division of，household responsibilities can be a major issue for newlyweds.By living together，couples can solve imbalances in the distribution of those responsibilities before someone realizes he or she has married a lazy bum.
This may seem like a small point，but how many women——and men——are out there who never thought they would be the only ones cooking，washing dishes，vacuuming，hopping，scrubbing，disinfecting，cleaning laundry，dusting，etc.？
One of the largest problems in marriages is the ’m’word：money.If couples live together before marriage，they learn one another’s saving and spending styles.By bating expenses，people learn not only how each person controls the purse strings but how to discuss finance matters with each other.It’s important for couples ’to figure out budget priorities before they are married，and this is difficult to do unless a person has been sharing expenses with his or her partner.If couples don’t have their financial sues in order，they are bound to surface；causing trouble in the marriage.
It’s also difficult to know someone intimately without living with him or her.A special bond forms between people who share their living space，their personal longings，and their lives together.Some things you just don’t know until you’ve lived with someone.
While some people believe living together before marriage is inappropriate，like most everything else in this country，it is a choice that everyone should respect.Living together can be a positive experience that will later reinforce a marriage，but it can also be something that ends a relationship.But if a relationship is going to end，it’s better people discover the hard troth before they marry.Even though two people love each other and enjoy spending time together，the real question is，Can you live together？People might want to find out before they make the serious decision to marry.