WORD PROBLEMS on Statistics 3 for Class 9 and 10
Question for practice
The following questions are more helpful for class tenth and class ninth students for all boards.
Questions 3. Naina has marks of 75, 82 and
90 in three mathematics tests. How many
marks must she obtain in the next test to have
an average of exactly 85 for the four math
tests?
Submit your answer here in the comments or wait for answer
The following questions are more helpful for class tenth and class ninth students for all boards.
Questions 3. Naina has marks of 75, 82 and
90 in three mathematics tests. How many
marks must she obtain in the next test to have
an average of exactly 85 for the four math
tests?
90 in three mathematics tests. How many
marks must she obtain in the next test to have
an average of exactly 85 for the four math
tests?
Submit your answer here in the comments or wait for answer
85= 75+82+90+x/4
ReplyDelete340= 75+82+90+x
x=340-247
x=93
therefore, she must obtain 93 marks in the next test!
Let the marks to be obtained in 4th test be x.
ReplyDelete85=82+75+90+x/4
85*4=247+x
340= 247+x
340-247=x
93=x
therefore, marks required in the 4th test to have an avg. of 85 is 93.
Ans. Mean of marks obtained in 4 tests = 85
ReplyDeletelet marks in 4th test = x
85 = 75 + 82 +90+x / 4
or 340 = 247 + x
or x = 93
therefore, Naina should get 93 marks in the 4th test to get an average of 85.
LET MARKS IN FOURTH TEST BE x.
ReplyDeleteTHEREFORE,
(75+82+90+x)/4=85
247+x=340
x=340-247
x=93
THEREFORE NAINA SHOULD OBTAIN A SCORE OF 93 IN HER 4TH TEST TO GET AN AVERAGE OF 85.