Respuesta :
Answer:
[tex]P_{20} = 20[/tex] --- 20th percentile
[tex]P_{25} = 21.75[/tex] --- 25th percentile
[tex]P_{65} = 27.85[/tex] --- 65th percentile
[tex]P_{75} = 29.5[/tex] --- 75th percentile
Step-by-step explanation:
Given
27, 24, 21, 16, 30, 33, 28, and 24.
N = 8
First, arrange the data in ascending order:
Arranged data: 16, 21, 24, 24, 27, 28, 30, 33
Solving (a): The 20th percentile
This is calculated as:
[tex]P_{20} = 20 * \frac{N +1}{100}[/tex]
[tex]P_{20} = 20 * \frac{8 +1}{100}[/tex]
[tex]P_{20} = 20 * \frac{9}{100}[/tex]
[tex]P_{20} = \frac{20 * 9}{100}[/tex]
[tex]P_{20} = \frac{180}{100}[/tex]
[tex]P_{20} = 1.8th\ item[/tex]
This is then calculated as:
[tex]P_{20} = 1st\ Item +0.8(2nd\ Item - 1st\ Item)[/tex]
[tex]P_{20} = 16 + 0.8*(21 - 16)[/tex]
[tex]P_{20} = 16 + 0.8*5[/tex]
[tex]P_{20} = 16 + 4[/tex]
[tex]P_{20} = 20[/tex]
Solving (b): The 25th percentile
This is calculated as:
[tex]P_{25} = 25 * \frac{N +1}{100}[/tex]
[tex]P_{25} = 25 * \frac{8 +1}{100}[/tex]
[tex]P_{25} = 25 * \frac{9}{100}[/tex]
[tex]P_{25} = \frac{25 * 9}{100}[/tex]
[tex]P_{25} = \frac{225}{100}[/tex]
[tex]P_{25} = 2.25\ th[/tex]
This is then calculated as:
[tex]P_{25} = 2nd\ item + 0.25(3rd\ item-2nd\ item)[/tex]
[tex]P_{25} = 21 + 0.25(24-21)[/tex]
[tex]P_{25} = 21 + 0.25(3)[/tex]
[tex]P_{25} = 21 + 0.75[/tex]
[tex]P_{25} = 21.75[/tex]
Solving (c): The 65th percentile
This is calculated as:
[tex]P_{65} = 65 * \frac{N +1}{100}[/tex]
[tex]P_{65} = 65 * \frac{8 +1}{100}[/tex]
[tex]P_{65} = 65 * \frac{9}{100}[/tex]
[tex]P_{65} = \frac{65 * 9}{100}[/tex]
[tex]P_{65} = \frac{585}{100}[/tex]
[tex]P_{65} = 5.85\th[/tex]
This is then calculated as:
[tex]P_{65} = 5th + 0.85(6th - 5th)[/tex]
[tex]P_{65} = 27 + 0.85(28 - 27)[/tex]
[tex]P_{65} = 27 + 0.85(1)[/tex]
[tex]P_{65} = 27 + 0.85[/tex]
[tex]P_{65} = 27.85[/tex]
Solving (d): The 75th percentile
This is calculated as:
[tex]P_{75} = 75 * \frac{N +1}{100}[/tex]
[tex]P_{75} = 75 * \frac{8 +1}{100}[/tex]
[tex]P_{75} = 75 * \frac{9}{100}[/tex]
[tex]P_{75} = \frac{75 * 9}{100}[/tex]
[tex]P_{75} = \frac{675}{100}[/tex]
[tex]P_{75} = 6.75th[/tex]
This is then calculated as:
[tex]P_{75} = 6th + 0.75(7th - 6th)[/tex]
[tex]P_{75} = 28 + 0.75(30- 28)[/tex]
[tex]P_{75} = 28 + 0.75(2)[/tex]
[tex]P_{75} = 28 + 1.5[/tex]
[tex]P_{75} = 29.5[/tex]