<span>Sister is 5 </span>
<span>Yan Ling is 9 </span>
<span>9+5=14 </span>
<span>1 less than twice 5 is 9.</span>
I will edit this after i calculat the answer just give me time
Your answer would be, <span>No, it is not a valid inference because her classmates do not make up a random sample of the students in the school </span>
(k - 34) x 9 =72
k - 34 = 72/9
k - 34 = 8
k = 8 + 34
k = 42
