Answer:
(1) The standard error is 0.0224.
(2) The error term is 0.058.
(3) The 99% confidence interval for the proportion of adults supporting the soft drink tax is (0.45, 0.57).
(4) Approximately 45% to 57% people support the soft drink tax.
Step-by-step explanation:
Let <em>X</em> = number of adults who support the soft drink tax.
The sample size is, <em>n</em> = 500.
The number of people who support the tax is, <em>X</em> = 255.
Compute the sample proportion as follows:
(1)
Compute the standard error as follows:
Thus, the standard error is 0.0224.
(2)
The error term (Margin of error) is:
For 99% confidence interval the critical value of <em>z</em> is:
Compute the value of MOE as follows:
Thus, the error term is 0.058.
(3)
Compute the 99% confidence interval as follows:
Thus, the 99% confidence interval for the proportion of adults supporting the soft drink tax is (0.45, 0.57).
(4)
The report to be submitted to the mayor is that approximately 45% to 57% people support the soft drink tax.