The mean length of 6 childrens' big finger is 6.7cm.
the mean length of 11 adults' big finger is 14.3cm.
what is the mean length (rounded to 2 dp) of these 17 people's big finger?
cm

New mean length of these 17 people=11.62

Step-by-step explanation:

Step 1: Determine the total length of children's fingers

L=l×n

where;

L=total length (cm)

l=mean length (cm)

n=number of children

replacing;

L=6.7×6=40.2 cm

The total children's fingers length=40.2 cm

Step 2: Determine the total length of adults fingers

total length of adults fingers=mean length of adults fingers×number of adults

where;

mean length of adults=14.3

number of adults=11

replacing;

total length of adults fingers=(14.3×11)=157.3 cm

Step 3: Determine the new mean length

new mean length=total length of adults and children fingers/number of adults and children

where;

total length of adults and children fingers=157.3+40.2=197.5 cm

number of adults and children=11+6=17

replacing;

new mean length=197.5/17=11.62

1/800 is the right answer