This data set represents the number of cups of coffee sold in a café between 8 a.m. and 10 a.m. every day for 14 days. {10, 9, 6, 12, 4, 6, 7, 8, 15, 14, 12, 9, 10, 5}. The difference of the values of the first and third quartiles of the data set is

Respuesta :

first arrange in ascending order:-

 4 5 6 6 7 8 9 9 10 10 12 12  14 15

first quartile = 6 and third quartile = 12

difference = 12-6  = 6

Answer:

The difference of the values of the first and third quartiles of the data set is 6.

Step-by-step explanation:

Data : 10, 9, 6, 12, 4, 6, 7, 8, 15, 14, 12, 9, 10, 5

This data set represents the number of cups of coffee sold in a café between 8 a.m. and 10 a.m. every day for 14 days.

Arrange the data in the ascending order :

4,5,6,6,7,8,9,9,10,10,12,12,14,15

No. of observations n = 14(even)

Median = [tex]\frac{(\frac{n}{2}+1)^{\text{th term}}+\frac{n}{2}^{\text{th term}}}{2}[/tex]

So, Median = [tex]\frac{(\frac{14}{2}+1)^{\text{th term}}+\frac{14}{2}^{\text{th term}}}{2}[/tex]

Median = [tex]\frac{8^{\text{th term}}+7^{\text{th term}}}{2}[/tex]

Median = [tex]\frac{9+9}{2}[/tex]

Median = [tex]\frac{18}{2}[/tex]

Median = 9

Now to find [tex]Q_3[/tex]  i.e. Third quartile

Consider the set of values right to the median .

9,10,10,12,12,14,15

Now find the median of this data

No. of observations n = 7(odd)

So, Median = [tex](\frac{n+1}{2})^{\text{th term}}[/tex]

= [tex](\frac{7+1}{2})^{\text{th term}}[/tex]  

= [tex](\frac{8}{2})^{\text{th term}}[/tex]

= [tex](4)^{\text{th term}}[/tex]

= [tex]12[/tex]

So, [tex]Q_3=12[/tex]  

Now to find [tex]Q_1[/tex]  i.e. First quartile

Consider the set of values left to the median .

4,5,6,6,7,8,9

No. of observations n = 7(odd)

So, Median = [tex](\frac{n+1}{2})^{\text{th term}}[/tex]

= [tex](\frac{7+1}{2})^{\text{th term}}[/tex]  

= [tex](\frac{8}{2})^{\text{th term}}[/tex]

= [tex](4)^{\text{th term}}[/tex]

= [tex]6[/tex]

So, [tex]Q_1=6[/tex]  

Now The difference of the values of the first and third quartiles of the data set  : 12-6=6

Hence The difference of the values of the first and third quartiles of the data set is 6