Answer: (a) H0: p = 0.2 versus Ha: p ≠ 0.2
(b) The test statistics is z- statistics = - 0.7071
(c) The P - value = 0.4796
(d) Conclude that the Firefox proportion is 0.2 because the P-value is larger than 0.01.
Step-by-step explanation: The test is a 2 - sided test , using the Z- statistics:
Sample mean = 36/200 = 0.18
Population mean = 0.2
Therefore:
Z = [tex]\frac{0.18 - 0.2}{\sqrt{\frac{0.2(1-0.2)}{200} } }[/tex]
= [tex]\frac{- 0.02}{\sqrt{\frac{0.2(0.8)}{200} } }[/tex]
= - 0.7071
Therefore , the test statistics = - 0.7071
(c) The P - value for the 2 - sided test implies
2 * P ( Z > /-0.7071/ ) = 0.4796
(d) Conclude that the Firefox proportion is 0.2 because the P- Value is larger than 0.01