Final answer:
After calculating the total height for the original and updated class, it's determined that the mean height of the new pupils is 139 cm. The provided options do not match this result, so there may be an error in the question or options.
Step-by-step explanation:
To determine the mean height of the new pupils, we start with the initial information that a class of 16 pupils has a mean height of 124 cm. After 4 new pupils join, the mean height increases to 127 cm. We can use this information to calculate the total height of all 20 pupils and then find out the total height of the 4 new pupils:
- Calculate the total height of the original 16 pupils: 16 pupils × 124 cm/pupil = 1984 cm.
- Calculate the new total height for 20 pupils: 20 pupils × 127 cm/pupil = 2540 cm.
- Subtract the total height of the original pupils from the new total to find the total height of the 4 new pupils: 2540 cm - 1984 cm = 556 cm.
- Finally, calculate the mean height of the 4 new pupils: 556 cm / 4 pupils = 139 cm per pupil.
Therefore, the mean height of the new pupils is 139 cm, which is not one of the options provided, indicating a possible error in the question or the given options.