Answer:
a) The box plot is attached. b) The lower limit is 46.5 and the upper limit is 86.5.
Step-by-step explanation:
The first step in creating a box plot is to order the data from least to greatest:
4,50,52,55,60,61,62,63,64,64,65,65,66,67,67,68,69,71,72,73,74,74,75,80
The median is the middle data value. This is between 65 and 66; this makes it
(65+66)/2 = 131/2 = 65.5.
The lower quartile, Q1, is the middle of the lower half of data. This is between 61 and 62; this makes it
(61+62)/2 = 123/2 = 61.5.
The upper quartile, Q3, is the middle of the upper half of data. This is between 71 and 72; this makes it
(71+72)/2 = 143/2 = 71.5.
This makes the interquartile range, IQR, 71.5-61.5 = 10.
The lower limit for outliers will be
61.5-1.5(10) = 61.5-15 = 46.5.
The upper limit for outliers will be
71.5+1.5(10) = 71.5+15 = 86.5.