Question 970259
Ho=0.47 of new car buyers will prefer a 4-door car.
Ha=NOT 0.47 of new car buyers will prefer a 4-door car (2 sided test)
alpha=0.05  P(reject Ho|when Ho is true)
Test statistic  randomly select 100 people (could be more or fewer) and see what the point estimate (the proportion of this group) is.

Critical value will be  |z|>1.96 for this 1-proportion test

z= p bar, (point estimate)-pi (p true) / sqrt [pi (1-pi)/n}  pi=0.47, the expected proportion.

If |z| >1.96, we will reject the null hypothesis and conclude that not 0.47 of new car buyers prefer a 4-door car.

If |z|<1.96, we will fail to reject the null hypothesis and conclude that there is insufficient evidence to conclude that 0.47 of new car buyers prefer a 4-door car