Final answer:
Calculating the 90% confidence interval for the 'muscle gap' requires more information than provided. We need the sample mean and sample size along with the standard deviation to determine the exact interval.
Step-by-step explanation:
To calculate the 90% confidence interval for the mean amount of muscle young men think they should add to be attractive to women, we first need to acknowledge the given information. We know that the distribution of the 'muscle gap' follows a normal distribution and has a standard deviation (σ) of 2.5kg/m². However, we do not have the sample mean or the size of the sample (n) given. To determine the confidence interval, we would typically use the formula for the confidence interval of a mean:
CI = ± Z * (σ / √n)
However, since we lack the sample mean and sample size, we cannot provide an exact interval. Instead, the options provided (A through D) seem to suggest expected margins of error for varying sample sizes at the 90 percent confidence level. These do not directly correlate with the calculation of a confidence interval without additional context such as the sample size and the Z-value for the 90% confidence level, which is approximately 1.645 for a normal distribution.
Given the insufficiency of data, an exact answer cannot be determined from the options provided (A through D).