Advertisements
Advertisements
प्रश्न
The mean of 35 observations is 20, out of which mean of first 18 observations is 15 and mean of last 18 observation is 25. Find the 18th observation.
उत्तर
Mean = `("sum of observations")/("Total number of observations")`
∴ sum of observations = Mean × Total number of observations
∴ sum of 35 observations = 20 × 35
= 700
Sum of first 18th observations = 15 × 18
= 270
Sum of last 18th observations = 25 × 18
= 450
18th observation = Sum of first 18 observations + Sum of last 18 observations - 35th observations
= 270 + 450 − 700
= 720 − 700
= 20
∴ The 18th observation is 20.
APPEARS IN
संबंधित प्रश्न
Find the common difference of the A.P 3, 5, 7, ..........
Ashish studies for 4 hours, 5 hours, and 3 hours respectively on three consecutive days. How many hours does he study daily on average?
A batsman scored the following number of runs in six innings: 36, 35, 50, 46, 60, 55. Calculate the mean runs scored by him in an inning.
The mean of a, b, c, d and e is 28. If the mean of a, c and e is 24, then mean of b and d is
If the average selling price of 15 books is ₹ 235, then the total selling price is __________
The average of the marks 2, 9, 5, 4, 4, 8, 10 is ____________
The marks of 14 students in a science test out of 50 are given below. 34, 23, 10, 45, 44, 47, 35, 37, 41, 30, 28, 32, 45, 39 Find the mean mark
The mean of first fifteen even numbers is ____________
Find the mean of first 10 prime numbers and first 10 composite numbers
The mean of three numbers is 40. All the three numbers are different natural numbers. If lowest is 19, what could be highest possible number of remaining two numbers?
