You are right i tried it and i got it right
Its 12 because 4 times 12 is 48 if you add 7 to 48 you get 55
Answer:
n=601
Step-by-step explanation:
Formula used:

Solution:

Where,

As there is no previous estimate for p
Then, p=0.5
Here on using the table

Also,
E=0.04
p=0.5
Thus,
n=600.2279407
On approximating the value,
n=601
The penny can land two ways.
The nickel can land two ways.
The dime can land two ways.
The quarter can land two ways.
The total number of ways that all of them can land is (2x2x2x2)= 16 possibilities.
Only ONE result shows no heads . . .
TAIL-TAIL- TAIL-TAIL.
All of the other 15 possibilities include at least one HEAD. So the probability is 15/16 = 93.25% .