Answer:
Tip $6
Total Amount $36
Step-by-step explanation:
20% of $30 is 6
$30 + $6 = 36
Complete Question
Educational Television In a random sample of 200 people, 159 said that they watched educational television. Find the 90% confidence interval of the true proportion of people who watched educational television. Round the answers to at least three decimal places.
Answer:
The 90% confidence interval is
Step-by-step explanation:
From the question we are told that
The sample size is n = 200
The number of people that watched the educational television is 
Generally the sample proportion is mathematically represented as

=> 
From the question we are told the confidence level is 90% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally the margin of error is mathematically represented as
=>
=>
Generally 95% confidence interval is mathematically represented as
=>
=>
Step-by-step explanation:
2x + 2y = 3 ( x2 for everything in the equation)
x - 4y = -1
4x+ 4y = 6
x - 4y = -1
Add the 1st line to the 2nd line to get rid of the y:
5x = 5
x - 4y = -1 ( you can pick any line from this system to be the second equation in this step, you can put 2x + 2y = 3 or 4x+ 4y = 6, anything above this step, but to make it simple chose the one you think is the easiest)
Solve for x, then plug the x value into the 2nd equation
x = 1
1 - 4y = -1
x = 1
-4y = -2 =) y = 1/2
x = 1
y= 1/2