First round to 6,020 then round 9 to 10 finally multiply to get 6,200
Answer:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.
Step-by-step explanation:
Confidence interval:
A confidence interval has the following format:
In which M is the sample mean, z is related to the confidence level and s is the standard error.
55% of U.S. adult Twitter users get at least some news on Twitter (Pew, 2013). The standard error for this estimate was 2.2%.
This means that
99% confidence level
So , z is the value of Z that has a pvalue of , so .
Lower bound of the interval:
Upper bound:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.
Answer:
x = 8
Step-by-step explanation:
since the triangle is isosceles then the 2 legs are congruent, that is both 4x - 3
the perimeter is the sum of the 3 sides , that is
x + 4x - 3 + 4x - 3 = 66
9x - 6 = 66 ( add 6 to both sides )
9x = 72 ( divide both sides by 9 )
x = 8
Answer:
14. x = 16; y = 23
15. x = 9; y = 13
Step-by-step explanation:
14. (4x + 4) = (7x - 44) (alternate exterior angles are congruent)
4x + 4 = 7x - 44
Collect like terms
4x - 7x = -4 - 44
-3x = -48
Divide both sides by -3
x = -48/-3
x = 16
39° + (8y - 43)° = 180° (consecutive exterior angles are supplementary)
39 + 8y - 43 = 180
Add like terms
-4 + 8y = 180
Add 4 to both sides
8y = 180 + 4
8y = 184
Divide both sides by 8
y = 184/8
y = 23
15. (15x - 26)° = (12x + 1)° (alternate exterior angles are congruent)
15x - 26 = 12x + 1
Collect like terms
15x - 12x = 26 + 1
3x = 27
Divide both sides by 3
x = 27/3
x = 9
28° + (12x + 1)° + (4y - 9)° = 180° (sum of interior angles of ∆)
Plug in the value of x
28 + 12(9) + 1 + 4y - 9 = 180
28 + 108 + 1 + 4y - 9 = 180
Add like terms
128 + 4y = 180
Subtract 128 from each side of the equation
4y = 180 - 128
4y = 52
Divide both sides by 4
y = 52/4
y = 13
62,900
21,000
126,300
856,700