Question

You apply for a job and have to take a drug test. You are curious about the error rate for the test so you do some research. You find a study where 47 out of 382 test results using this test were wrong (either a false positive or a false negative). The company that produces the drug test claims that less than 14% of the test results are wrong. Test if this seems accurate.

Answer 1

Answer:

Test statistic  Z = -1.0

 |Z| = |-1.0| < 1.96 at 0.05 level of significance.

The null hypothesis is accepted

The company that produces the drug test claims that less than 14% of the test results are wrong

Step-by-step explanation:

Step(i):-

Given that the population proportion P = 14% =0.14

Given that the sample size 'n' = 382 tests

Given that find a study where 47 out of 382 test results using this test were wrong (either a false positive or a false negative).

Sample proportion

                        $p = \frac{x}{n} = \frac{47}{382} = 0.1230$

Null hypothesis: H₀ : P = 0.14

Alternative Hypothesis:H₁ : P≠ 0.14

Step(ii):-

Test statistic

              $Z = \frac{p-P}{\sqrt{\frac{PQ}{n} } }$

         $Z = \frac{0.1230-0.14}{\sqrt{\frac{0.14 X0.86}{382} } }$

       Z = - 1.0

     |Z| = |-1.0| < 1.96 at 0.05 level of significance.

Final answer:-

The null hypothesis is accepted

The company that produces the drug test claims that less than 14% of the test results are wrong