Margin of error, e = Z*SD/Sqrt (N), where N = Sample population
Assuming a 95% confidence interval and substituting all the values;
At 95% confidence, Z = 1.96
Therefore,
0.23 = 1.96*1.9/Sqrt (N)
Sqrt (N) = 1.96*1.9/0.23
N = (1.96*1.9/0.23)^2 = 262.16 ≈ 263
Minimum sample size required is 263 students.
Answer:
Step-by-step explanation:
2)
a) elimination method
b) substitution method
c) substitution method
For the first part we can elimate the y variable by subtracting the equations. We can then find the value of x.
For the second part we can substitute y as 2x+5 in the second equation and solve for x.
For the third part we can substitute y as 4x+3 in the first equation and solve for x.
3)
Answer:
D
Step-by-step explanation:
The answer is 6
The lengths of the line segments are summarized in the following list:
- DF = 3
- DE = 8 / 3
- FG = 3
- FH = 9 / 2
- GH = 3 / 2
- EH = - 11 / 6
<h3>How to calculate the length of a line segment based on point set on a number line</h3>
Herein we have a number line with five points whose locations are known. The length of each line segment is equal to the arithmetical difference of the coordinates of the rightmost point and the leftmost point:
DF = - 1 - (- 4)
DF = 3
DE = (- 1 - 1 / 3) - (- 4)
DE = 3 - 1 / 3
DE = 8 / 3
FG = 2 - (- 1)
FG = 3
FH = (3 + 1 / 2) - (- 1)
FH = 4 + 1 / 2
FH = 9 / 2
GH = (3 + 1 / 2) - 2
GH = 1 + 1 / 2
GH = 3 / 2
EH = (3 + 1 / 2) + (- 1 - 1 / 3)
EH = - 2 + (1 / 2 - 1 / 3)
EH = - 2 + 1 / 6
EH = - 11 / 6
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Answer:
n = 1
Step-by-step explanation:
Represent the number by n. Then "seven less than twice a number is -5 becomes 2n - 7 = -5
Next we must solve for n. Adding 7 to both sides yields 2n = 2, so that
n = 1
