HCD 300 Exam 2 UPDATED QUESTIONS
AND CORRECT ANSWERS
Central Limit Theorem - CORRECT ANSWER As you sample size increases, your distribution
will more closely approximate a normal distribution
Normal Distribution - CORRECT ANSWER data will be around a central value with no bias
left or right
Skewness - CORRECT ANSWER Measure of the asymmetry of the distribution
Symmetrical distribution has a skew of 0
If the skew is more than 2 or less than -2, the skew is substantial
Positive Skew - CORRECT ANSWER Right skewed
long tail to the right
mean is higher than the median
Negative Skew - CORRECT ANSWER Left-skewed
long tail to the left
mean is lower than the median
Kurtosis - CORRECT ANSWER Measure of how peaked or flat the distribution is.
* if excess kurtosis is more than 2 or less than -2, the kurtosis is substantial
Leptokurtic - CORRECT ANSWER higher peak, positive value
Mesokurtic - CORRECT ANSWER Normal, Value of 0
Platykurtic - CORRECT ANSWER Flatter peak, negative value
, The Z-Score - CORRECT ANSWER standard score that is the result of dividing the difference
of raw score from the mean of the distribution by the standard deviation
Z= X- U/ Std dev
calculate using formula
Excel (STANDARDIZE function)
Z-score: Scores below ( to the left of) - CORRECT ANSWER the mean are negative
Z-score: Scores above ( to the right of) - CORRECT ANSWER the mean are positive
Z-Score
Sample size over 30
population standard deviation is known - CORRECT ANSWER Z= X-U/ std
T- Score
Sample size under 30
population standard deviation is unknown - CORRECT ANSWER t= x-x/ s
A description of how peaked or flat a distribution is - CORRECT ANSWER Kurtosis
T/F: Symmetrical distribution has a skew of 0 - CORRECT ANSWER True
This is the % of the distribution that falls within one standard deviation of the normally distributed
mean - CORRECT ANSWER 68%
A distribution where the median is less than the mean is considered? - CORRECT
ANSWER Positively skewed, left modal
When a sample is greater than 30 we use this to standardize a score - CORRECT ANSWER z
score
AND CORRECT ANSWERS
Central Limit Theorem - CORRECT ANSWER As you sample size increases, your distribution
will more closely approximate a normal distribution
Normal Distribution - CORRECT ANSWER data will be around a central value with no bias
left or right
Skewness - CORRECT ANSWER Measure of the asymmetry of the distribution
Symmetrical distribution has a skew of 0
If the skew is more than 2 or less than -2, the skew is substantial
Positive Skew - CORRECT ANSWER Right skewed
long tail to the right
mean is higher than the median
Negative Skew - CORRECT ANSWER Left-skewed
long tail to the left
mean is lower than the median
Kurtosis - CORRECT ANSWER Measure of how peaked or flat the distribution is.
* if excess kurtosis is more than 2 or less than -2, the kurtosis is substantial
Leptokurtic - CORRECT ANSWER higher peak, positive value
Mesokurtic - CORRECT ANSWER Normal, Value of 0
Platykurtic - CORRECT ANSWER Flatter peak, negative value
, The Z-Score - CORRECT ANSWER standard score that is the result of dividing the difference
of raw score from the mean of the distribution by the standard deviation
Z= X- U/ Std dev
calculate using formula
Excel (STANDARDIZE function)
Z-score: Scores below ( to the left of) - CORRECT ANSWER the mean are negative
Z-score: Scores above ( to the right of) - CORRECT ANSWER the mean are positive
Z-Score
Sample size over 30
population standard deviation is known - CORRECT ANSWER Z= X-U/ std
T- Score
Sample size under 30
population standard deviation is unknown - CORRECT ANSWER t= x-x/ s
A description of how peaked or flat a distribution is - CORRECT ANSWER Kurtosis
T/F: Symmetrical distribution has a skew of 0 - CORRECT ANSWER True
This is the % of the distribution that falls within one standard deviation of the normally distributed
mean - CORRECT ANSWER 68%
A distribution where the median is less than the mean is considered? - CORRECT
ANSWER Positively skewed, left modal
When a sample is greater than 30 we use this to standardize a score - CORRECT ANSWER z
score
