Answer:
95% Confidence interval: (31.32%,47.04%)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 148
Number of people who sleep for 8 hours or longer, x = 58
95% Confidence interval:
Putting the values, we get:
(31.32%,47.04%) is the required 95% confidence interval.
Answer:
Option B. 
Step-by-step explanation:
we know that
The frequency is equal to the number of cycles divided by the time
Remember that
1 cycle = 1 full wave to repeat itself
In this problem
From o to 12 seconds ------> there are 2 cycles
therefore
The frequency is equal to

Answer:
70
Step-by-step explanation:
Finding the common denominator is really just finding the gcf of 7 and 10. The gcf of 7 and 10 is 70. So the common denominator is 70.
We have to add the amounts:
4(2x+3y) + 3(5x+4)
First, though, we have to distribute:
4*2x + 4*3y + 3*5x + 3*4
8x + 12y + 15x + 12
Now we just need to simplify:
23x + 12y + 12
The students planted 23x + 12y + 12 trees total.