SEE QUESTION IN IMAGE

Answer:
Step-by-step explanation:
[tex]Mean=\frac{all.ages.added.together.of.all.kids}{total.number.of.kids}[/tex] Hopefully, that makes sense! To get the numerator of that problem, we take the number of kids and multiply it by the corresponding age and add them all together. To get the denominator, we add the total number of kids together. That will look like this mathematically, setting the mean equal to 14.44, as stated:
[tex]14.44=\frac{13(15)+14(42)+15X+16(10)+17(3)}{15+42+X+10+3}[/tex] and simplify that a bit to
[tex]14.44=\frac{195+588+15X+160+51}{70+X}[/tex] and a bit more to
[tex]14.44=\frac{994+15X}{70+X}[/tex] and cross multiply
14.44(70 + X) = 994 + 15X and
1010.8 + 14.44X = 994 + 15X and
16.8 = .56X so
X = 30
30 kids are 15 years old for the mean age to be 14.44
d.30
Answer:
Solution given:
x. [tex] \:\:\:[/tex] f. [tex] \:\:\:[/tex] fx
13. [tex] \:\:\:[/tex] 15. [tex] \:\:\:[/tex] 195
14.[tex] \:\:\:[/tex] 42 [tex] \:\:\:[/tex] 588
15. [tex] \:\:\:[/tex] x. [tex] \:\:\:[/tex] 15x
16. [tex] \:\:\:[/tex] 10. [tex] \:\:\:[/tex] 160
17. [tex] \:\:\:[/tex] 3. [tex] \:\:\:[/tex] 51
. n=70+x. [tex]\sum[/tex]=994+15x
we have
mean=sum/n
14.44=[tex]\bold{\frac{\sum}{n}}[/tex]
14.44=[tex]\bold{\frac{994+15x}{70+x}}[/tex]
doing crisscrossed multiplication
(70+x)*14.44=994+15x
1010.8+14.44x=994+15x
15x-14.44x=1010.8-994
0.56x=16.8
x=16.8/0.56
x=30