# math

posted by .

On a certain exam, Tony corrected 10 papers and found
the mean for his group to be 70. Alice corrected the remaining
20 papers and found that the mean for her
group was 80. What is the mean of the combined group
of 30 students?

• math -

10 * 70 = 700
20 * 80 = 1600

700 + 1600 = 2300
2300 / 30 = ?

• math -

76.6

## Similar Questions

1. ### Completely Randomized ANOVA

Forty eight subjects were randomly assigned to one of 4 treatment conditions in a study of different methods of coping with statistics exam anxiety. After the experiment, 12 subjects remained in group 1, 8 in group 2, 10 in group 3, …
2. ### statistics

To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of …
3. ### statistics

suppost we wanted to test the hypothesis that control a group of cancer patients(group 1) would report higher mean pain ratings than an experimental group recieving special message treatment(group 2). Use the following information, …
4. ### statistics

the mean marks obtained by a group of 100 students was found to 49.46.THE mean marks obtained in the same examination by another group of 200 students was 52.32. Find the mean marks obtained by the both groups of students tken together.
5. ### res/342

To test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of …
6. ### UOP

o test the hypothesis that students who finish an exam first get better grades, Professor Hardtack kept track of the order in which papers were handed in. The first 25 papers showed a mean score of 77.1 with a standard deviation of …
7. ### Math

9 students in a group found that their mean score was 86 for the first math test. On the next test, each student in the group scored 7 points higher than on the first text. What was their mean score for the two tests?
8. ### Stats

A study found that for adults the general self-efficacy scale mean score was 35 and standard deviation was 12. A group of clients (n=14) was measured for their general self-efficacy with the same measure and found having 40 with standard …
9. ### CHM Lab

Calibration of a 50 ml buret (10 ml,15 ml,20ml, 25 ml,30ml,35ml,40ml,45ml,50ml)(repeated the procedure 3 times) for experimental ; i have observed vol(ml) , temp.C ,for true i have mass(g), true vol. ml and for calibration i found …
10. ### math

Jenny must sit four papers for an exam. The mean of the first three papers Jenny has sat is 72%. (a)If she wants to get an overall mean of at least 75%,what is the lowest mark she can get in her fourth paper?

More Similar Questions