Question

A manufacturer of automobile products has developed a new wax and is interested in comparing the new wax with their standard wax to determine
if the new wax will protect a car for a longer period of time.   In order to make a comparison, both waxes are applied to five new cars respectively and
exposed to the same environmental conditions. The results of the test are:

     Standard Wax                                          New Wax

n₁  = 5                                                     n₂ = 5

       x bar 1   = 86.80 hours of effectiveness          x bar 2   = 92.40 hours of effectiveness

        s₁  = 2.88 hours                                       s₂ = 2.49 hours

The standard error for this test is:

Answer 1

Standard error

$= \sqrt{s_1^2/n_1 + s_2^2/n_2}$

$= \sqrt{2.88^2/5 + 2.49^2/5}$

= 1.703