Statistics task

Question

I have very simple math task to solve but as am not a math person, I would kindly ask for your help. The task: 30% of students failed test.the test average score was 7.5 and standart deviation was 1.3. What was the needed score to pass the test? That's all info I have. Hope it makes sense. Thank you

Answer 1

Assume a normal distribution of test scores. Approximately 68% of the marks will lie inside 1 standard deviation. So the approximately 16% of the students will have marks less than 7.5-1.3=6.2

Since 50% of the students have marks less than 7.5, it's reasonable to set a passing score of 7.5-(1.3/2)=6.85