Usually the easiest way to solve this is by using a calculator. Of course only if your teacher allows you too.
Answer:
The 95% confidence interval for the proportion of American adults who smoked in 2008 is (20.1%, 21.1%).
Step-by-step explanation:
The critical value of <em>z</em> for 95% confidence level is:
<em>z</em> = 1.96
Compute the 95% confidence interval for the proportion of American adults who smoked in 2008 as follows:
Thus, the 95% confidence interval for the proportion of American adults who smoked in 2008 is (20.1%, 21.1%).
Answer:
no
Step-by-step explanation:
x = 4/5
2/5=1/2x
Step 1: Flip the equation.
1/2x=2/5
Step 2: Multiply both sides by 2.
2*(1/2x)=2*(2/5)x=4/5
The two formulas i used should be in your book