99%; n = 17; o is unknown; population appears to be normally distributed.
za/2 = 2.583
za/2 = 2.567
Ota/2 = 2.898
Ota/2 = 2.921

answer: the answer is 35%

attachment?

step-by-step explanation:

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!