Answer:
The 95% confidence interval for the true percentage of all adults over 30 who shop at that mall who admit to having lost their car at the mall is (25.37%, 43.93%).
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 z-score that has a p-value of 
.
Of 101 randomly selected adults over 30 who frequent a very large mall, 35 admitted to having lost their car at the mall.
This means that 
95% confidence level
So 
, z is the value of Z that has a p-value of 
, so 
.
The lower limit of this interval is:
The upper limit of this interval is:
As percentages:
0.2537*100% = 25.37%
0.4393*100% = 43.93%
The 95% confidence interval for the true percentage of all adults over 30 who shop at that mall who admit to having lost their car at the mall is (25.37%, 43.93%).
Answer:
Step-by-step explanation:
"The difference between A and B" means "A - B". "Is no more than" means "is less than or equal to." Applying these translations to your statement gives ...
x - 3 ≤ 2
Adding 3 to both sides of this inequality tells you its solution:
x ≤ 5
EQUATION 1: x-y=12
EQUATION 2: 3x+y=4
STEP 1:
solve for one variable in equation 1
x - y= 12
add y to both sides
x= 12 + y
STEP 2:
use x value from step 1 and substitute in equation 2
3x + y= 4
3(12 + y) + y= 4
multiply 3 by parentheses
(3*12) + (3*y) + y= 4
multiply inside parentheses
36 + 3y + y= 4
combine like terms
36 + 4y= 4
subtract 36 from both sides
4y= -32
divide both sides by 4
y= -8
STEP 3:
substitute y value from step 2 into either equation
x - y= 12
x - (-8)= 12
x + 8= 12
subtract 8 from both sides
x= 4
CHECK:
x= 4, y= -8
3x + y= 4
3(4) + (-8)= 4
12 - 8= 4
4= 4
ANSWER: The x value is 4 and the y value is -8.
Hope this helps! :)
Answer:A on edge
Step-by-step explanation:
Answer:
1 is biased, 2 isn't, 3 is biased, 4 isnt
Step-by-step explanation:
If you ask a question to people in a group who are already clearly for a certain topic then it is biased. For survey to not be biased, the people need to be chosen at random. Ask students what their favorite class is, or ask flight attendants where their favorite destination to travel to is. Dont use a group who has any relation to the survey at hand. Asking band students about funding for band is biased, as well as asking people who are at a SOCCER GAME what their favorite sport is.
