Mathematics
Assertion (A): Mean of n observations is x and mean of another set of n observations is y, the combined mean of all the observations is x+y/2 Reason (R): Total number of observations = nx + ny ∴ Mean of all the observations = nx+ny/2n 1. A is true, but R is false. 2. A is false, but R is true. 3. Both A and R are true, and R is the correct reason for A. 4. Both A and R are true, and R is the incorrect reason for A.
Related Questions
Statement 1: The mean of 100 observation is 50 and one of these observation is increased by 150, the sum of resulting observation is 100 x 50 + 150.
Statement 2: The sum of resulting observation = 100 x 50 + 100.
Both the statements are true.
Both the statements are false.
Statement 1 is true, and statement 2 is false.
Statement 1 is false, and statement 2 is true.
Assertion (A): The mean of x1, x2 and x3 is m. Then the value of (x1 - m) + (x2 - m) + (x3 - m) = 0.
Reason (R): x1 + x2 + x3 = 3m
⇒ (x1 - m) + (x2 - m) + (x3 - m) = (x1 + x2 + x3) - 3m
A is true, but R is false.
A is false, but R is true.
Both A and R are true, and R is the correct reason for A.
Both A and R are true, and R is the incorrect reason for A.
The mean of 100 observations is 40. It is found that an observation 53 was misread as 83. Find the correct mean.
The mean of 200 items was 50. Later on, it was discovered that two items were misread as 92 and 8 instead of 192 and 88. Find the correct mean.