Question

The mean of 20 items is 40 and the means of another 30 item is 60.What is the mean of whole set of item?​

Answer 1

Hey mate here we go

$the \: 1st \: means \: of \: 20 \: items \: is \: 40 \: means \: \\ its \: total \: is \: 40 \times 20 = 800 \\ \: now \: 2nd \: mean \: \\ i.e \: 30 \times 60 = 1800 \\ \: now \: they \: asked \: for \: whole \: items \: \\ therefore \: total \: items \: are \: 20 + 30 = 50 \\ \: total \: of \: 800 + 1800 = 2600 \\ \: nw \: whole \: means \: is \\ mean = \frac{2600}{50} = 52 \\ there \: we \: got \: whole \: means \: is \: 52 \\ i \: hope \: this \: will \: help \: u \\ mark \: my \: ans \: as \: brainliest$

Answer 2

The mean is 52

Step-by-step explanation:

$Mean = \frac{\text{Sum of all observations}}{\text{No. of observations}}$

The mean of 20 items is 40

So,$40 = \frac{\text{sum of 20 items}}{20}$

$40 \times 20 = \text{sum of 20 items}$

$800= \text{sum of 20 items}$

The means of another 30 item is 60

$60 = \frac{\text{Sum of 30 item}}{30}$

$60 \times 30 = \text{Sum of 30 item}$

$1800=\text{Sum of 30 item}$

Sum of 50 item = 1800+800=2600

Mean =$\frac{2600}{50}=52$

Hence The mean is 52

#Learn more:

Find the average of 12 number if first 8numbers average is 21 find the average of last 4 numbers

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