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In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66. What are the lower and upper limits of a box-and-whiskers display of this data

Respuesta :

MrRoyal

Answer:

[tex]L =52[/tex] --- Lower Limit

[tex]U =82[/tex] --- Upper Limit

Step-by-step explanation:

Given

[tex]N = 10[/tex]

[tex]Data: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66[/tex]

Required

Determine the lower and upper limits of box and whisker display

First, arrange the data in ascending order

The sorted data is:

[tex]Data: 65, 66, 67, 68, 71, 73, 74, 77, 77, 77[/tex]

The lower limit (L) is calculated using:

[tex]L = Q_1 - 1.5 * (Q_3-Q_1)[/tex]

The upper limit (U) is calculated using:

[tex]U =Q_3 + 1.5 * (Q_3-Q_1)[/tex]

Q1 is calculated using:

[tex]Q_1 = \frac{1}{4}(N+1)[/tex]

[tex]Q_1 = \frac{1}{4}(10+1) = 2.75 = 3rd\ data[/tex]

[tex]Q_1 = 67[/tex]

Q3 is calculated using:

[tex]Q_3 = \frac{3}{4}(N+1)[/tex]

[tex]Q_3 = \frac{3}{4}(10+1) = 8.25= 8th\ data[/tex]

[tex]Q_3 = 77[/tex]

So:

[tex]L = Q_1 - 1.5 * (Q_3-Q_1)[/tex]

[tex]L =67 - 1.5*(77-67)[/tex]

[tex]L =67 - 1.5*10[/tex]

[tex]L =67 - 15[/tex]

[tex]L =52[/tex]

[tex]U =Q_3 + 1.5 * (Q_3-Q_1)[/tex]

[tex]U =67 + 1.5*(77-67)[/tex]

[tex]U =67 + 1.5*10[/tex]

[tex]U =67 + 15[/tex]

[tex]U =82[/tex]