Answer: b) 84
Step-by-step explanation:
Let p be the prior estimate of the required proportion.
As per given , we have
p =0.5 (The probability of getting heads on a fair coin is 0.5)
Significance level : 
Critical z-value (using z-value table ) : 
Confidence interval width : w= 0.18
Thus , the margin of error : 
Formula to find the sample size ( if prior estimate of proportion is known.):-

Substitute the values , we get

Simplify ,
[Round of to the next whole number.]
Hence, the number of times we would have to flip the coin =<u>84</u>
hence, the correct answer is b) 84
Answer:
B
Step-by-step explanation:
Edge
Lo que se divide se llama dividendo, que se divide por el divisor, y el resultado se llama cociente. En el ejemplo, 20 es el dividendo, 5 es el divisor y 4 es el cociente.
This is not an integer; an integer is a whole number that can be positive, negative, or zero such as -1, 0, and 1.