unimodal curve? - ANSWER normal distribution
In a normal distribution, the mean is located where? - ANSWER in the middle of the
curve
T/F For a normal curve, the median, mean, and mode are typically equal
T/F The area below the curve is 120%. - ANSWER True
False. 100% or 1.00
T/F The greater the standard deviation, the less spread out the normal curve. - ANSWER
FALSE
The greater the standard deviation, the more spread out the normal curve. The smaller the
standard deviation, the narrower the normal curve.
A normal distribution can be defined by its ___ and ______. - ANSWER mean and stand-
ard deviation
the ___-___-___ rule
con? - ANSWER 68-95-99.7
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, However, the rule only works when values are exactly 1, 2, or 3 standard deviations away
from the mean. In order to apply the concept of proportions to other standard deviation val-
ues, such as σ = ± 1.4 or σ = ± 2.3, scores or values in the dataset must be standardized.
an exact value that is observed - ANSWER raw score
indicates exactly how many standard deviations a raw score is above or below the mean. -
ANSWER standard score
describes the exact location of a raw score within the whole distribution when compared to
the mean. It converts each raw score X into a signed, numerical value.
also known as standard scores - ANSWER z-score
What does a +z-score mean?
what does a -z-score mean? - ANSWER the value from the dataset lies above the mean
the value from the dataset lies below the mean
Coverting raw scores to z-scores - ANSWER z= (raw score- mean)/ standard deviation
Converting z-scores to raw scores - ANSWER raw score= mean + z * standard deviation
Comparing Values using z-Scores and Raw Scores
When comparing z-scores from the same population or sample, it may be more meaningful
to convert the z-score back to a raw score. For example, compare the performances of the
following students on the physiology exam (μ = 87 , σ = 4 ) given the -scores listed below for
Josef, Marco, and Brooklyn.
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