The following data represent the repair cost for a low-impact collision in a simple random sample of mini and micro-vehicles (such as the Chevrolet Aveo or Mini Cooper), it was verified that the data come from a population that is normally distributed with no outliers and s = $1007.4542. Construct and interpret a 90% confidence interval for the standard deviation repair cost of a low-impact collision involving mini- and micro-vehicles.
$3148 $1758 $1071 $3345 $743
$2057 $773 $1370 $663 $2637

Now we just take square root on both sides of the interval and we got:

For this case we can conclude that the true deviation at 90% of confidence is between 734.783 and 1657.489

Step-by-step explanation:

The confidence interval for the population variance is given by the following formula:

The sample deviation is s=1007.4542

The degrees of freedom are:

The confidence is 0.90 or 90%, and the significance would be and , and the critical values are:

Replacing the info given we got:

Now we just take square root on both sides of the interval and we got:

For this case we can conclude that the true deviation at 90% of confidence is between 734.783 and 1657.489

-362

step-by-step explanation:

(12)(4)+2(12)-34(12)+2(12)-3

  \/         \/         \/         \/

  48 +   24 -   408 + 24 - 3

      \   /               \   /

          72     -     432 - 3 = -363