The following boxplot is of the birth weights (in ounces)of 160 infants born in a local hospital. Approximately __________ children had birth weights between 102 and 122 ounces.
A)40
B)50
C)80
D)100

Question

The following boxplot is of the birth weights (in ounces)of 160 infants born in a local hospital.  Approximately __________ children had birth weights between 102 and 122 ounces.
A)40 
B)50 
C)80 
D)100

Quizplus · Accepted Answer

From the boxplot, we can determine that the interquartile range (IQR) is approximately 24 ounces (from the first quartile at around 112 ounces to the third quartile at around 136 ounces). Therefore, any birth weight within one IQR of the median (which is around 122 ounces) is considered to be within the "middle 50%" of the data. 102 ounces is one IQR below the median, and 122 ounces is directly on the median, so we can estimate that approximately 50% of the infants (which is half of 160, or 80 infants) had birth weights between 102 and 122 ounces.

The Following Boxplot Is of the Birth Weights (In Ounces)of