Well, since we know that 39 diamonds are needed for 3 chandeliers, it would be helpful to know how many diamonds are needed for 1 chandelier. To find this, we can divide 39 by 3 to see she needs 13 diamonds for one chandelier. Now, all you need to do is multiply 13 by the number of chandeliers Stacia is making! 13 x 4 is 52, and 13 x 10 is 130. Therefore, if she wanted to make 4 chandeliers, she would need 52 diamonds. If she wanted to make 10 chandeliers, Stacia would need 130 diamonds.
Hope I helped! <3