Answer:
60 students
Step-by-step explanation:
The confidence interval of a proportion is given by:

Where 'p' is the proportion of students who responded 'yes', 'z' is the z-score for a 95% confidence interval (which is known to be 1.960), and 'n' is the number of students in the sample.
If the confidence interval is from 0.584 to 0.816, then:

60 students were in the sample.
Well, 1/3 is equal to 0.3, and 1/4 is equal to .25, so it can't be a.
3/4 is equal to .75 and 6/9 is equal to 0.6, so it can't be b.
5/8 is equal to 0.625 and 20/32 is also equal to 0.625, so it could be c.
7/9 is equal to 0.7 and 21/28 is equal to 0.75, so it can't be D.
Your best bet is C. Because both sides of C are equal.
C 5/8=20/32
Answer:
an = 80. 2^(n-5)
Step-by-step explanation:
r = a6/a5 =160/80 = 2
an = a5. r^(n-5)
= 80. 2^(n-5)
5*23
Note 23 = 20 + 3
5*23 = 5*(20 + 3) and by distributive property
5*23 = 5*20 + 5*3 = 100 + 15 = 115
= 115