A single coin is tossed 300 times. Heads were observed 180 times. What is the long-run relative frequency of tails? Express the answer in decimal form..

To find the long-run relative frequency of tails, we first need to calculate the number of times tails appeared in the 300 coin tosses.

Total number of coin tosses = 300
Number of times heads appeared = 180

Number of times tails appeared = Total number of coin tosses - Number of times heads appeared
Number of times tails appeared = 300 - 180
Number of times tails appeared = 120

Now, we can calculate the proportion of tails relative to the total number of tosses:

Relative frequency of tails = Number of times tails appeared / Total number of coin tosses
Relative frequency of tails = 120 / 300
Relative frequency of tails = 0.4

Therefore, the long-run relative frequency of tails is 0.4.