Question

UULUT

Answer 1

Answer:

The first error she made in computing the variance was to have placed -1,024 instead of +1,024

Step-by-step explanation:

we have the data set

87, 46, 90, 78, and 89

step 1

Find the mean

$(87+46+90+78+89)/5$

$390/5=78$

step 2

Subtract the Mean for each value of data set and square the result  and then adds the numbers

$(87-78)^{2}+(46-78)^{2}+(90-78)^{2}+(78-78)^{2}+(89-78)^{2}$

$(9)^{2}+(-32)^{2}+(12)^{2}+(0)^{2}+(11)^{2}$

$81+1,024+144+0+121$

so

The first error she made in computing the variance was to have placed -1,024 instead of +1,024

$1,370$

step 3

Work out the mean of those squared differences

$1,370/5=274$ ----> this value is called the "Variance"