STATS 110 EXAM 2 QUESTIONS AND
ANSWERS (VERIFIED AND UPDATED)
Varibles must be measured with a _______. What two types? - ANS number, categorical or
quantitative
What is data? - ANS the measurement of all variables considered
What are the two sources of measurement error? - ANS bias and random error
For a quantitative variable what does the measured variable equal? - ANS measured value =
true value + bias + random error
What is the goal? - ANS to calculate the true value
What is a bias measurement? - ANS a measurement that is currently under or above the true
value
What is a random error measurement? - ANS a repeated measurement on the same subject
gives different results
Unbiased - ANS accurate
@2026/2027 ALLRIGHTS RESERVED.
, Low variability - ANS low random error
High precision - ANS high variability
Suppose your scale at home always weighs you as 5 pounds less than true weight? - ANS the
scale would be negatively biased (usually arises because of the instrument used)
If the random error is small? - ANS the measurement is reliable
What does a perfectly reliable and unbiased measurement have? - ANS 0 variability
How do we calculate range? - ANS max-min
Postive bias - ANS measurements are higher than the true value
Negative bias - ANS measurements are lower than the true value
What does the statistical principal of averaging reduce? - ANS variability
What is standard deviation? - ANS measure of spread in relation to the mean
The larger the standard deviation... - ANS the more the measurement varies
How do we remove bias? - ANS typically need to change the instrument
One attempt to remove error? - ANS average measurements together
@2026/2027 ALLRIGHTS RESERVED.
ANSWERS (VERIFIED AND UPDATED)
Varibles must be measured with a _______. What two types? - ANS number, categorical or
quantitative
What is data? - ANS the measurement of all variables considered
What are the two sources of measurement error? - ANS bias and random error
For a quantitative variable what does the measured variable equal? - ANS measured value =
true value + bias + random error
What is the goal? - ANS to calculate the true value
What is a bias measurement? - ANS a measurement that is currently under or above the true
value
What is a random error measurement? - ANS a repeated measurement on the same subject
gives different results
Unbiased - ANS accurate
@2026/2027 ALLRIGHTS RESERVED.
, Low variability - ANS low random error
High precision - ANS high variability
Suppose your scale at home always weighs you as 5 pounds less than true weight? - ANS the
scale would be negatively biased (usually arises because of the instrument used)
If the random error is small? - ANS the measurement is reliable
What does a perfectly reliable and unbiased measurement have? - ANS 0 variability
How do we calculate range? - ANS max-min
Postive bias - ANS measurements are higher than the true value
Negative bias - ANS measurements are lower than the true value
What does the statistical principal of averaging reduce? - ANS variability
What is standard deviation? - ANS measure of spread in relation to the mean
The larger the standard deviation... - ANS the more the measurement varies
How do we remove bias? - ANS typically need to change the instrument
One attempt to remove error? - ANS average measurements together
@2026/2027 ALLRIGHTS RESERVED.
