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:
less than
Step-by-step explanation:
If x = # of quarters, then, the # of dimes will be equal to 2x. The total value (z) would be equal to:
z = 0.25x + 0.10(2x)
Then, since you switch the quarters and the dimes, and you have a new total, the resulting equation will be:
1.2 + z = 0.25(2x) + 0.10(x)
Plug in the values you know:
1.2 + (0.25x + 0.10(2x)) = 0.25(2x) + 0.10(x)
Solve for x:
1.2 + (0.25x + 0.20x) = 0.50x + 0.10x
1.2 + 0.45x = 0.60x
1.2 = 0.15x
x = 1.2/0.15 = 8
This means that there are 8 Quarters in her bag right now. So, the amount of dimes is just 2x which is 16. So your answer will be:
She has 8 Quarters and 16 Dimes in her bag right now. Or, $3.60.
If this doesn't make sense, then tell me. I have some resources where I got the answer from to put it into simplest terms. I have the website if you want.
Answer:
By doubling each day
Step-by-step explanation:
Jay is increasing daily a fixed amount of pennies to his collection. That's an arithmetic series, because to obtain the next term you have to do an addition.
To get a geometric series or progression you have to find the next term through multiplication.
So, if he wants to convert his series into a geometric series, he'd have to double his contribution to his collection each day (as an example).
First you would take 20% off the orignal price giving you 30.4$ after that you take 10% of 30.4 to get 27.36$.