Final answer:
The question is about finding probability and percentile for a mean stress score. More information is needed to provide accurate calculations.
Step-by-step explanation:
The given question is related to statistics and is about finding the probability and percentile for a mean stress score. However, the provided references and examples do not cover the specific context of the question. Therefore, it is necessary to analyze the question independently.
Probability:
To find the probability that the mean stress score for the 75 students is less than 2, we need to assume a distribution for the data. Without this information, we cannot calculate the probability. Please provide additional details regarding the distribution of the stress scores.
Percentile:
The 90th percentile for the mean stress score for the 75 students can be found by first determining the critical value associated with the desired percentile using the z-table or a calculator. Once the critical value is obtained, it can be used to find the mean stress score corresponding to the 90th percentile.