Question

you flip 3 coins 20 times and record the number of heads. the results are listed below.
2, 1, 0, 2, 2, 0, 2, 2, 3, 2, 1, 2, 1, 2, 1, 1, 2, 1, 3, 1
complete the frequency table.
a = $\boldsymbol{square}$ ; b = $\boldsymbol{square}$; c = $\boldsymbol{square}$;
d = $\boldsymbol{square}$

number of heads	frequency
1	$b$
2	$c$
3	$d$

retry

Explanation:

Step1: Count frequency of 0 heads

Count how many times 0 appears in the data set: 0 appears 2 times. So $a=2$.

Step2: Count frequency of 1 head

Count how many times 1 appears in the data set: 1 appears 7 times. So $b=7$.

Step3: Count frequency of 2 heads

Count how many times 2 appears in the data set: 2 appears 8 times. So $c=8$.

Step4: Count frequency of 3 heads

Count how many times 3 appears in the data set: 3 appears 3 times. So $d=3$.
(Verification: $2+7+8+3=20$, which matches the total number of trials)

Answer:

$a=2$, $b=7$, $c=8$, $d=3$

Completed frequency table:

Number of Heads	Frequency
1	7
2	8
3	3