Answer:
a)
b)
Step-by-step explanation:
Polar coordinates are represented as: , where 'r' is the length (or magnitude) of the line, and '' is the angle measured from the positive x-axis.
in our case:
to covert the polar to cartesian:
we can plug in our values:
the Cartesian coordinates are:
(b) to convert (x,y) = (6.06,-3.5)
we'll use the pythagoras theorem to find 'r'
the angle can be found by:
to convert radians to degrees:
writing in polar coordinates:
Answer:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
For this problem, we have that:
95% confidence level
So , z is the value of Z that has a pvalue of , so .
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).
<span>50b 50=11b 95 collect the like terms
50b-11b=95-50
39b=45 divide both sides by 39
b=1.2</span>