Question

Each of three friends flips a coin 70 times. The results for each friend are shown in the tables. Find the relative frequency for the event ​"tails​" for each friend. If the friends combine their results to get 131 heads and 79 ​tails, what is the relative frequency for the event ​"tails​"? Use pencil and paper. Suppose each friend flips a coin 700 times. Is there a value you would expect the relative frequency for the event ​"tails​" to be close​ to?
Friend 1
Outcome
Frequency
   Heads
32
   Tails
38
Friend 2
Outcome
Frequency
   Heads
52
   Tails
18
Friend 3
Outcome
Frequency
   Heads
47
   Tails
23
Question content area bottom
Part 1
The relative frequency for the event ​"tails​" for Friend 1 is
  
0.54.
​(Type an integer or a decimal rounded to the nearest hundredth as​ needed.)
Part 2
The relative frequency for the event ​"tails​" for Friend 2 is
  
enter your response here.
​(Type an integer or a decimal rounded to the nearest hundredth as​ needed.)

Answer 1

Relative frequency = (number of tails) / (number of flips).

- Friend 1: 38/70 = 0.542857... → 0.54 (given)
- Friend 2: 18/70 = 0.257142... → 0.26
- Friend 3: 23/70 = 0.328571... → 0.33

Combined (131 heads, 79 tails): 79/(131+79)=79/210 = 0.37619... → 0.38

If each friend flips 700 times (large number of flips), you would expect the relative frequency for tails to be close to 0.50 (the probability of tails for a fair coin).