To construct the grouped frequency table, we need to divide the range from \( 41.5 \) kg to \( 61.5 \) kg into five equal intervals.

\( \text{Total range} = 61.5 - 41.5 = 20 \) kg

\( \text{Class width} = \dfrac{20}{5} = 4 \) kg

The intervals are:

• 41.5–45.5
• 45.5–49.5
• 49.5–53.5
• 53.5–57.5
• 57.5–61.5

Next, count the number of weights in each interval:

• 41.5–45.5: 45, 44, 45 (4 weights)
• 45.5–49.5: 47, 49, 46, 48, 49 (7 weights)
• 49.5–53.5: 50, 51, 52, 50, 51, 52, 51, 53, 52, 53 (10 weights)
• 53.5–57.5: 55, 55, 54, 56, 57 (5 weights)
• 57.5–61.5: 58, 59, 60, 61 (4 weights)

Thus, the frequencies for each interval are \( 4,\ 7,\ 10,\ 5,\ 4 \) respectively.