Question

exam scores: there are two sections of a mathematics course. section a has 10 students and section b has 20 students. all students took the same final exam. the mean score in section a was 52, and the mean score for all 30 students was 70. what was the mean score in section b? round to one decimal place, if necessary.
the mean exam score in section b is

Explanation:

Step1: Calculate total score of all students

The formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, so the total score of all 30 students is $70\times30 = 2100$.

Step2: Calculate total score of section A students

The total score of 10 students in section A is $52\times10=520$.

Step3: Calculate total score of section B students

The total score of section B students is the total score of all students minus the total score of section A students, so it is $2100 - 520=1580$.

Step4: Calculate mean score of section B students

The mean score of 20 students in section B is $\frac{1580}{20}=79.0$.

Answer:

79.0