Cogs 14B Final Review

Descriptive statistics help us infer things about populations from sample data.

An ice cream shop sells 50 cones per day. The population mean = 45 and sd = 0.5. Is the z score 4

beta is the probability of getting an effect under the null hypothesis.

Is this histogram normally distributed?

If everything in the previous question was the same but the sample size increases what would happen?

SSx and SSy can be negative

students in a class scored a 450 on the SAT. hypothetical pop mean = 400, and se = 15. is the class helping?

How would you compare measures of central tendency in positively-skewed distribution

Calculate the population standard deviation for 2,4,6,8,10

failing to reject the null hypothesis is a type 2 error

p value is the probability that the null hypothesis is true

How are the z and t-test different?

Median can be used for

if the null is true what is the probability of making a type 1 error

standard error can be larger than population sd

pop mean = 80, sample mean = 87, n = 10 and SS = 30. Is the null rejected?

the sum of deviations from the mean of a distribution must be equal

Descriptive statistics _______________ variability

Mean can be used for ______ data

what is the skew?

measure the grade distribution in a class (A+ to F). What scale is this measured on?

mean ht of a person is 6 ft, and sd=3 ft. You want to know the actual ht of a person whose z score = -1.

1,2,3,3,3,3,4,5,5,6,6,6,7,7,7,8,8,8,8,8,8,9,9,9,9,9,9,10. This data forms a negatively skewed slope

n = 10, alpha = 0.5, what is t?

what would the null hypothesis in an independent sample test look like?assume population mean

at what f value is the null hypothesis true

probability of getting an A in this class? (include P/NP)

sample mean is a biased estimator

to obtain a statistically significant f ratio

is p value is lesser than alpha then the result is statistically significant

f = MS within/MS between

power can be increased by_____

the sample mean can be identical to the population mean

What does the z score tell you?

as sample size increases the standard error of the mean decreases.

what does having n-1 in the denominator while calculating sample standard deviation do?

if n increases the standard error increases

What ensures a causal relationship when analyzing a sample. Additionally, it ensures generalizability.

Population standard deviation (sigma) = root(SS/N)

choose the correct options

distributions can have the same mean but different variability

Probability can be negative

if you have a negatively skewed distribution. Which measure of central tendency will likely be the largest?

A statistic is any data

Examples of inferential statistics

Type 2 error is incorrectly rejecting the null

The probability of detecting an effect is called p-value

standard error of the mean = population sd / root n

f statistic = variability between groups/variability within groups

MS within = SS Within/df within

mode can be used for

test that tells us if the difference between two groups is significant

as sample size increases, the shape of the distribution of sample means becomes normal

Examples of descriptive statistics

Which of the following is an odd one out?