Math 200 Midterm

Systematic Sample

Sample members from a large population are selected according to random starting point but with fixed periodic interval

Simple Random Sample

A subset of a statistical population in which each member has an equal probability of being chosen

How do you find the standard deviation of a probability distribution

Square root of the sum of x minus the mean squared divided by n minus 1

What sampling methods do you know?

Stratefied Sample, Cluster Sample, Random Sample, Simple Random Sample, Systematic Sample

What types of data can you collect?

Categorial(qualitative), Numerical(quantitative), Continuous, Discrete

Categorical

Qualitative

Numerical

Quantitative

Continuous

You can't list up; Area=probability

Discrete

Binomial distribution

How can you measure the center of the distribution?

Mean, Median, Mode, Midrange

Median

M=P50 (can resist outlier)

Mode

Center by frequency

Midrange

Xmax+Xmin divided by 2

How can you measure the variation(Spread)?

Range, Standard Deviation, Variance

Range

Xmax-Xmin

Variance

Before square root of standard deviation (same as standard deviation but squared

Normal Distribution

Mean is 0 and Standard Deviation is 1

What does it mean by 2 events are independent?

No affect on one another

How do you find the mean of a probability distribution?

X(bar) = Sum of X divided by N

Do you know how to count systematically?

5!, 25C5, 25P5

Mean

Sample = x, Population = u (Sum(x) divided by sample size)9affected by an outlier)

Standard Deviation

Sample= S, Population = squiggly

How can you measure the relative standing within the distribution?

Z Score, Percentile, Box-Plot = 5 number summary

What fact do you know about probability?

In between 0 and 1, Sum is 1, P(A) + P(complementA) = 1

What does it mean by 2 events are disjoint?

P(AnB) = 0

P(AnB)

P(A given B)

P(AuB)

P(A) + P(B)

What kind of probability do you remember?

P(A), P(AuB), P(AnB), P(A/B)

In order to find probability, we need:

Experiment outcomes

Empirical Rule

68, 95, 99.7

How do you describe distribution?

Center, Variation, Gap, Outlier

Probability histogram is the probability bar graph for ------- variable.

Discrete

Binomial Mean:

u = NP

Binomial Standard deviation:

Square root of NPQ

What determines the binomial distribution?

n and p

Random Sample

Selection is based on chance and everyone has a non zero probability of being selected

Cluster Sample

Researcher divides the population into separate groups and a sample of clusters is selected

Stratefied Sample

Researcher divides the population into separate groups and a sample is drawn from each group

Combination

Order does not matter, n!/r!(n-r)

Permutation

order matters

n!/(n-r)!

Continuous Variable

Obtained by measuring

Discrete Variable

Obtained by counting

What is the standard normal distribution?

mean of 0 and standard deviation of 1

What determines the normal distribution

Mean and standard deviation

What is the binomial experiment?

N is finite, P stays the same, only 2 outcomes, each trial is independent

What is X in a pay off table?

Random Variable