Inferential statistics is the process of using sample results to draw conclusions about the characteristics of a population
Mean: Standard Deviation:
If population of individual measurements is normal, x is normal
Sample size (n ≥ 30), x is normal
To convert any random variable X to standardized normal random variable Z:
To determine the percentile using z-score, use normalcdf(lower, upper, mean, standard deviation).
To determine Z using the given area from the left of the bell curve and standard deviation, use invNorm(probability, mean, standard deviation). If using the right, use invNorm(1 – probability, mean, standard deviation).
Confidence interval when standard deviation is known:
When standard deviation is unknown, use T.
Is population proportion (p) normal? np ≥ 5 and n(1-p) ≥ 5
To determine confidence interval when giving p = x/n, use 1-PropZInt
QMS 202 Quiz #1 Crib Sheet
Inferential statistics is the process of using sample results to draw conclusions about the characteristics of a population
Mean: Standard Deviation:
If population of individual measurements is normal, x is normal
Sample size (n ≥ 30), x is normal
To convert any random variable X to standardized normal random variable Z:
To determine the percentile using z-score, use normalcdf(lower, upper, mean, standard deviation).
To determine Z using the given area from the left of the bell curve and standard deviation, use invNorm(probability, mean, standard deviation). If using the right, use invNorm(1 – probability, mean, standard deviation).
Confidence interval when standard deviation is known:
When standard deviation is unknown, use T.
Is population proportion (p) normal? np ≥ 5 and n(1-p) ≥ 5
To determine confidence interval when giving p = x/n, use 1-PropZInt