Question 1193396
<font color=black size=3>
Answers:
a) <font color=red>0.1</font>
b) <font color=red>0.0614</font>


The answer to part (a) had been rounded (it was initially 0.08)
The answer for part (b) is approximate. Round it however you need to.
The more accurate value is roughly 0.061399431050567


=============================================================
Explanations:


a)


The population proportion p is best estimated by the sample proportion phat (symbol *[tex \large \hat{p}])
We pronounce it as "p-hat" since the letter p has a hat on top.
The point estimate is the center of the confidence interval.


x = number of people who asked their physician about a drug they saw on tv
x = 6
n = sample size
n = 75


So,
phat = x/n
phat = 6/75
phat = 0.08
phat = <font color=red>0.1</font> when rounding to one decimal place


------------------------
b)


Use a table like this one
<a href = "https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf">https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf</a>
to look at the bottom row marked in blue (it starts with Z)
The value 1.960 is just above the 95% confidence level.


What this means is P(-1.960 < Z < 1.960) = 0.95 approximately.
z = 1.960 is the approximate critical value for a 95% confidence level.


E = margin of error
E = z*sqrt(phat*(1-phat)/n)
E = 1.960*sqrt(0.08*(1-0.08)/75)
E = 0.061399431050567
E = <font color=red>0.0614</font>
This value is approximate.
</font>