Question

the mean height of 8 students is 152 cm .two more students of hieghts 143 cm and 156 cm join the group .what is new mean height​

Answer 1

Answer:

New mean height is 151.5 cm.

Step-by-step explanation:

We know,

Mean = Sum of observations / no. of observations

Here,

= > 152 cm = ( Sum of heights of 8 students ) / 8

= > 152 cm x 8 = Sum of heights of 8 students

= > 1216 cm = Sum of heights of 8 students

Now, when two more students of heights 143 cm and 156 cm have joined the group.

= > Sum of heights of 10 students = sum of heights of 8 students + sum of heights of newly joined students

= > 1216 cm + 143 cm + 156 cm

= > 1515 cm

No. of students : 10

= > New mean = 1515 cm / 10

= > New mean = 151.5 cm

Answer 2

$\huge{\underline{\underline{\red{\mathfrak{Question :}}}}}$

the mean height of 8 students is 152 cm .two more students of hieghts 143 cm and 156 cm join the group. What is new mean height ?

$\huge{\underline{\underline{\red{\mathfrak{Answer :}}}}}$

$\tt {\pink{Given}} \begin{cases} \sf{\green{Mean \: height \: = \: 152 \: cm}} \\ \sf{\blue{Number \: of \: Students}} \end{cases}$

We know that Formula for mean is :

$\large{\underline{\boxed{\sf{Mean \: = \: \dfrac{Sum \: of \: Observations}{Number \: of \: Observations}}}}}$

Put Values

⇒152 = Sum of observations/8

⇒Sum of observations = 152*8 = 1216

∴ Sum of Heights = 1216 cm

________________________________

A.T.Q,

If two more observations are added of height 143 cm and 156 cm

Then ,

Total Number of students = 8 + 2 = 10

Total Height = 1216 + 143 + 156 = 1515 cm

Now put above values in formula of mean

⇒Mean = 1515/10

⇒Mean = 151.5 cm

$\Large{\boxed{\sf{Mean \: Height \: = \: 151.5 \: cm}}}$