STATS 121 EXAM 2 QUESTIONS WITH VERIFIED
ANSWERS
As confidence level increases, width... - answers - increases
As n (sample size) decreases, the width.... - answers - increases--bc less
accurate so margin of error and interval increases
T-distribution - answers - almost the same as the standard normal
distribution
Mean= 0
Bell-shaped, symmetric
"heavier" tails (more area underneath) than standard normal
Larger df/n=closer to standard normal (z distribution)
Confidence interval is used to estimate.... - answers - the value of
population parameter
Parameter is for... - answers - population
Statistic is for... - answers - sample mean
Sigma - answers - standard deviation of a population
Mu - answers - population mean
S - answers - standard deviation of a sample mean/x-bar
X-bar - answers - sample mean
Degrees of freedom (df) - answers - n-1
How to find t* on table
Confidence statement requirements - answers - 1. Statement of confidence
2. Parameter of interest
3. The interval
, Point estimator - answers - x-bar
Confidence multiplier - answers - z*/t*
Margin of error (m) - answers - z*(sigma/sq root (n)) or t*(s/sq root (n))
Standard deviation of point estimator - answers - sigma/sq root (n)
Standard error of x-bar - answers - s/sq root (n)
Estimate of standard deviation of sampling distribution of x-bar (aka
sigma/sq root n) - answers - s/sq root (n)
Same as standard error of x-bar
4 steps for tests of significance - answers - state, plan, solve, conclude
One-sided test - answers - ho > < = to ha
Two-sided test - answers - ho differs from/does not equal ha
As n increases, the chance to reject ho.... - answers - increases
As n increases, the test statistic... - answers - increases
Decreasing alpha ____ beta and _____power - answers - increases beta,
decreases power
Increasing alpha ____ beta and _____ power - answers - decreases beta,
increases power
Alpha and beta have a(n) __________ relationship - answers - inverse
Beta and power have a(n) _____ relationship - answers - inverse
Alpha and power have a(n) ____ relationship - answers - direct
As n increases, power ________. - answers - power increases
(therefore, beta decreases)
ANSWERS
As confidence level increases, width... - answers - increases
As n (sample size) decreases, the width.... - answers - increases--bc less
accurate so margin of error and interval increases
T-distribution - answers - almost the same as the standard normal
distribution
Mean= 0
Bell-shaped, symmetric
"heavier" tails (more area underneath) than standard normal
Larger df/n=closer to standard normal (z distribution)
Confidence interval is used to estimate.... - answers - the value of
population parameter
Parameter is for... - answers - population
Statistic is for... - answers - sample mean
Sigma - answers - standard deviation of a population
Mu - answers - population mean
S - answers - standard deviation of a sample mean/x-bar
X-bar - answers - sample mean
Degrees of freedom (df) - answers - n-1
How to find t* on table
Confidence statement requirements - answers - 1. Statement of confidence
2. Parameter of interest
3. The interval
, Point estimator - answers - x-bar
Confidence multiplier - answers - z*/t*
Margin of error (m) - answers - z*(sigma/sq root (n)) or t*(s/sq root (n))
Standard deviation of point estimator - answers - sigma/sq root (n)
Standard error of x-bar - answers - s/sq root (n)
Estimate of standard deviation of sampling distribution of x-bar (aka
sigma/sq root n) - answers - s/sq root (n)
Same as standard error of x-bar
4 steps for tests of significance - answers - state, plan, solve, conclude
One-sided test - answers - ho > < = to ha
Two-sided test - answers - ho differs from/does not equal ha
As n increases, the chance to reject ho.... - answers - increases
As n increases, the test statistic... - answers - increases
Decreasing alpha ____ beta and _____power - answers - increases beta,
decreases power
Increasing alpha ____ beta and _____ power - answers - decreases beta,
increases power
Alpha and beta have a(n) __________ relationship - answers - inverse
Beta and power have a(n) _____ relationship - answers - inverse
Alpha and power have a(n) ____ relationship - answers - direct
As n increases, power ________. - answers - power increases
(therefore, beta decreases)
