Answer:
b. 8.7
Step-by-step explanation:
Answer 19:1
Work:
Students scoring above 80 -
9+18+72+15= 114
Students score exactly 80-
6
114/6 = 19
19 students scored above 80 for every 1 student that scored exactly 80.
Answer:

Step-by-step explanation:
We are given the following equation:

We have to convert it into polar form.
We put

Putting values, we get:

is the required polar form.
The number of terms, 'n' is 8
<h3 /><h3>How to determine the number of terms</h3>
Let's determine the common ratio;
common ratio, r = 3/1 = 3
The formula for sum of geometric series with 'r' greater than 1 is given as; Sn = a( r^n - 1) / (r - 1)
n is unknown
Sn = 3280
Substitute the value
3280 = 1 ( 3^n - 1) / 3- 1
3280 = 3^n -1 /2
Cross multiply
3280 × 2 = 3^n - 1
6560 + 1 = 3^n
6561 = 3^n
This could be represented as;
3^8 = 3^n
like coefficient cancels out
n = 8
Thus, the number of terms, 'n' is 8
Learn more about geometric series here:
brainly.com/question/24643676
#SPJ1
we are given that
angle(ACF)=90
angle(ACB)=61
sum of all angles along any line is 180
so, we get
angle(ACF)+angle(ACD)=180
we can plug value
90+angle(ACD)=180
angle(ACD)=90
now, we can use formula
angle(ACD)=angle(ACB)+angle(BCD)
now, we can plug values
and we get
90=61+angle(BCD)
90-61=61-61+angle(BCD)
angle(BCD)=29................Answer