Question

The mean of 15 numbers is 18 and the mean of 10 numbers is 13 what is the mean of
all the 25 number​

Answer 1

Answer:

16

Step-by-step explanation:

Average of set 1=Total sum/15

$18 = total \: sum \div 15 \\ total \: sum = 15 \times 18 = 270$

Average of set 2=Total sum/10

$13 = total \: sum \div 10 \\ tota \: sum = 13 \times 10 = 130$

$sum \: of \: all \: numbers = 270 + 130 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 400$

$no. \: of \: values = 15 + 13 = 25$

$average = 400 \div 25 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 16$