Saturday

March 28, 2015

March 28, 2015

Posted by **preston** on Thursday, October 2, 2008 at 2:52am.

- math -
**bobpursley**, Thursday, October 2, 2008 at 8:45amThe mean above 70 is 81, the mean of the students below is 60.

Let nf be the number of students that failed.

sumfaildgrades+sumpassedgrades=total sum grades.

nf*60+(42-nf)81=42(75.5)

check that. solve for nf.

**Answer this Question**

**Related Questions**

hard math - 42 students took a test in school where the passing score was 70. ...

math algebra - 42 students took a test in school where the passing score was 70...

math - 42 students took a test in school where the passing score was 70. the ...

math - 42 students took a test in school where the passing score was 70. the ...

Statistics - Students were given an exam with 300 multiple-choice questions. The...

math - The mean score on a Math exam was 50% and the standard deviation was 10...

Statistics - A group of 56 randomly selected students have a mean score of 30.8 ...

Stats - A group of 56 randomly selected students have a mean score of 30.8 and a...

statistics - Suppose that the mean score of an exam was 77 when taken 30 ...

statistics - Suppose that the mean score of an exam was 77 when taken 30 ...