stats unit 7 Flashcards
POI for proportions
The POI is the true population proportion of ____.
A ssumptions for proportions
1) stated random sample
2) 10% condition
3) n(p-hat) >(or equal to) 10
n(q-hat) >(or equal to) 10
(we can assume to use approx. normal)
N aming the interval for proportions
One sample z-interval for proportions
Calc part for proportions
stat–>test–>option A
interval interpretation
We are __% confident that the interval from ___ to ___ captures the true _(context)__.
finding n for proportions
MOE = z-star sqr-root p-hat(q-hat) / n
(write it out)
ALWAYS ROUND UP
if p-hat is unknown …
p-hat = .5
(also known as a conservative p-hat)
confidence level (sentence)
If we make many __% confidence intervals, we expect about ___% to capture the true __(context)__.
(percents are the same value)
POI for mean
The POR is the true average ____context___.
A ssumptions for mean
1) stated random sample
2) 10% condition
3) - stated that population is normal
- n >(or equal to) 30 (CLT check)
- no strong skew or outliers (GRAPH)
—>we can assume to use approx. normal
N aming the Interval for mean
One sample for t-interval for means
Calc for mean
stat–>test–>#8
C onclusion foe mean must include…
UNITS
Solving for n
MOE = t-star (standard deviation /sqr-root n
write down the equation for mean
write down the equation for proportions
an increase in n means
the closer to normal the curve gets (narrower)
df
n-1
Tax
Zap
Given a list…
DATA
“pieces parts”…
STATS
increase in n means
MOE decreases
increase in confidence level means
MOE increases
x =
of successes
when z-star gets smaller
z-star moves closer to Mu
when st. deviation gets smaller
there is less variation
when n gets larger
we get a better picture of pop
interpret MOE (write down)
If the experiment repeated many times, then the sample ___(x or p) will be within ___ of the true population about __% of the…
The margin of error ONLY includes
the SAMPLING VARIABILITY (the sample)
construct and interpret –>
PANIC
