Question

the table displays the scores of students on a recent exam. find the mean of the scores to the nearest 10th.
score number of students
55 1
60 5
65 6
70 1
75 7
80 7
85 2
90 9

Explanation:

Step1: Calculate the sum of the products

Multiply each score by the number of students and sum them up.
\[ (55\times1)+(60\times5)+(65\times6)+(70\times1)+(75\times7)+(80\times7)+(85\times2)+(90\times9) \]
\[ = 55 + 300+390 + 70+525+560+170+810 \]
\[ = 2880\]

Step2: Calculate the total number of students

Sum up the number of students in each score - group.
\[1 + 5+6 + 1+7+7+2+9\]
\[= 38\]

Step3: Calculate the mean

Divide the sum of the products by the total number of students.
\[ \text{Mean}=\frac{2880}{38}\approx75.8\]

Answer:

75.8