Answer :

Sure, let's calculate the average alcohol content of the given beers by volume step-by-step.

### Step 1: List the given alcohol content values

The provided alcohol content values are:
- 4.80%
- 12.00%
- 40.00%
- 7.20%

### Step 2: Add up the alcohol content values

We need to find the total alcohol content by summing these values:
[tex]\[ 4.80 + 12.00 + 40.00 + 7.20 \][/tex]

### Step 3: Calculate the sum
[tex]\[ 4.80 + 12.00 = 16.80 \][/tex]
[tex]\[ 16.80 + 40.00 = 56.80 \][/tex]
[tex]\[ 56.80 + 7.20 = 64.00 \][/tex]

The total sum of the alcohol content values is 64.00%.

### Step 4: Determine the number of values

Count the number of given alcohol content values. There are four values provided.

### Step 5: Calculate the average

To find the average, we divide the total sum by the number of values:
[tex]\[ \text{Average} = \frac{\text{Total Sum}}{\text{Number of Values}} \][/tex]
[tex]\[ \text{Average} = \frac{64.00}{4} \][/tex]

### Step 6: Compute the average

[tex]\[ \text{Average} = 16.00 \][/tex]

Thus, the average alcohol content of the given beers by volume is [tex]\( \boxed{16.00\%} \)[/tex].