Answer :
Final answer:
To find the mean, we took the midpoint of 1.1m and 1.7m, which is 1.4m. For standard deviation, we divided the interval's half-width by 1.96 and got approximately 0.153m. However, Option A fits the closest to our calculation with a mean of 1.4m and a standard deviation of 0.3m.
Explanation:
The question asks to calculate the mean and standard deviation for the height of students, given that the middle 95% falls between 1.1m and 1.7m and that height follows a normal distribution. We know that the middle 95% corresponds to the interval between -1.96 and +1.96 standard deviations from the mean in a normal distribution.
Using this information:
- The total width of the interval is 1.7m - 1.1m = 0.6m.
- The width of half the interval, which corresponds to 1.96 standard deviations, is 0.3m.
- Therefore, one standard deviation is approximately 0.3m / 1.96 ≈ 0.153m.
- To find the mean, we take the midpoint of the interval: (1.1m + 1.7m) / 2 = 1.4m.
Thus, the mean height of the students is 1.4m, and the standard deviation is approximately 0.153m. However, as the standard deviation must be from the given options, the closest is 0.3m. The correct option in the final answer that matches our calculations is Option A: Mean = 1.4m, Standard Deviation = 0.3m.
