5/11 × -9/14 + 5/11 × 5/11 × -4/13
Answer in fraction
Answers
Answer:
6/4
Step-by-step explanation:
★ Given:
Marks (out of 100) obtained by a group of students in science test = 85, 76, 90, 85, 39, 48, 56, 95, 81 and 75
\bigstar★ To Find:
Highest and the lowest marks obtained by the students.
Range of marks obtained.
Mean marks obtained by the group.
\bigstar★ Solution:
In order to find the highest and lowest marks, we have to arrange the marks in ascending order as follows:
Ascending order: 39, 48, 56, 75, 76, 81, 84, 85, 90, 95
The highest mark is 95 and the lowest is 39.
The range of the marks obtained = (95-39)=56(95−39)=56
From the given information, we have,
Mean marks = \sf\frac{Sum \: of \: the \: marks}{Total\: number \: of \: students}
Totalnumberofstudents
Sumofthemarks
Mean marks = (39 + 48 + 56 + 75 + 76 + 81 + 84 + 85 + 90 + 95)(39+48+56+75+76+81+84+85+90+95) ÷ 1010
\implies 729⟹729 ÷ 1010
\implies 72.9⟹72.9
Hence, the mean mark of the students is 72.9.
5/11 × -9/14 + 5/11 × 5/11 × -4/13
LCM of 14 & 11 = 154
5/11 × -99/154 + 70/154 × 5/11 × -4/13
5/11 × -29/154 × 5/11 × -4/13
= 2900/242242
= 1450/121121 (Simplest form)