Answer:
D. We can be 95% confident that the proportion of all cell phone users who use text messaging is between 73.1% and 76.9%.
Step-by-step explanation:
The interpretation of a confidence interval of level x% means that we are x% sure that the interval contains the true mean of the population.
In this problem, we have that:
The population are all the cell phone users.
The 95% confidence interval is (73.1%, 76.9%).
Which of the following is an appropriate interpretation of the 95% confidence interval?
D. We can be 95% confident that the proportion of all cell phone users who use text messaging is between 73.1% and 76.9%.
Answer:
It might be 1/3 but I'm not 100% sure
M/_A= 120°
m/_B=30°
m/_C= 100°
sum of all the angles=120+30+100 = 250°
Rooms sold / total # rooms
90/115 = .78
Occupancy rate = 78%
Answer:
10 kph
Step-by-step explanation:
Find the speed of the current of the river.
20/(20 - c) + 180/(20 + c) = 8
20(20 + c) + 180(20 - c) = 8(400 - c^2)
8c^2 - 160c + 800 = 0
8(c^2 - 20c + 100) = 0
8(c - 10)^2 = 0
c = 10
The speed of the current of the river is 10 km/hour.
