Question

An experiment was conducted to measure the effectiveness of various feed supplements on the growth rate ofchickens. A five number summary of the weights of the chicks in grams six weeks after hatching is as follows.Source: Anonymous (1948) Biometrika, 35, 214.• Min = 101• Q1 - 209• Median = 262• Q3-312• Max = 4251. Aboutpercent of the chicks weigh more than 209.2. Aboutpercent of the chicks weigh more than 262.3. Aboutpercent of the chicks weigh more than 312.4. Aboutpercent of the chicks weigh between 209 and 312.

Answer 1

Recall that the first quartile is equivalent to the 25th percentile, meaning that 25% of the population is below the first quartile and 75% of the population is above the first quartile.

The median is the number in the "middle" of the set, meaning that 50% of the population is above the median and 50% is below the median.

The third quartile is equivalent to the 75th percentile, meaning that 25% percent of the population is above the third quartile and 75% is below the third quartile.

Therefore:

75% of the chicks weigh more than 209 because 209 is the first quartile.

50% of the chicks weigh more than 262 because 262 is the median.

25% of the chicks weigh more than 312 because 312 is the third quartile.

For the last question: we know that about 75% of the chicks weigh less than 312, but only 75% weigh more than 209 therefore, about 50% weigh between 209 and 312.

Answer:

1.- 75%

2.- 50%

3.-25%

4.- 50%