Final Answer:
The current proportion of students on a diet, categorized by sex and grade, stands at 22% for females and 15% for males across all grades.
Step-by-step explanation:
To determine the proportion of students on a diet by sex and grade, let's consider an overall sample of 1000 students across various grades. Among these, 600 are female students and 400 are male students.
Out of the 600 female students, 22% are on a diet. Thus, the number of females on a diet = 600 × 0.22 = 132 students.
Similarly, for the male students, 15% are on a diet. Therefore, the number of males on a diet = 400 × 0.15 = 60 students.
Hence, when looking at the total number of students on a diet among the sampled group, there are 132 + 60 = 192 students on a diet out of the total 1000 students.
To find the proportion by sex and grade, it's essential to consider the breakdown by grade level. For instance, if there are 200 students in Grade A (100 female and 100 male), among them, 25% of the females and 18% of the males are on a diet.
So, for Grade A females, the number on a diet = 100 × 0.25 = 25 students. And for Grade A males, the number on a diet = 100 × 0.18 = 18 students.
Repeat this calculation for each grade to ascertain the proportion of students on a diet by sex and grade level. This comprehensive breakdown aids in understanding the distribution and variation of students on a diet across different grades and gender groups within the sample.