Answer:
The 95% confidence interval based on this sample is =
[6.41, 7.79]
Step-by-step explanation:
The formula for Confidence Interval =
Mean ± z × standard deviation/√n
Sample mean = 7.1 hours
Standard deviation = 5 hours
n = 200 students
z = 95% confidence interval z score
= 1.96
C.I = 7.1 ± 1.96 × 5/√200
C.I = 7.1 ± 0.693
Hence, Confidence Interval
= 7.1 - 0.693
= 6.407
Approximately = 6.41
= 7.1 + 0.693
= 7.793
Approximately = 7.79
Therefore, the 95% confidence interval based on this sample is
[6.41, 7.79]
9514 1404 393
Answer:
140°
Step-by-step explanation:
Angles 1 and 3 are "corresponding" angles, so are congruent.
∠1 = ∠3
20x +60 = 30x +20
40 = 10x . . . . . . . . . . . . subtract 20x+20
4 = x . . . . . . . . . . . . . . divide by 10
∠1 = 20x +60 = 20(4) +60 = 80 +60
∠1 = 140°
The answer is 20.
5*10-5*6=50-30=20
