Sarah's reasoning sounds good to start. She rounded the available bags and their content, so the result, 4000 bracelets, should be really easy to reach.
The exact numbers are 214 bags * 22 bracelets / bag = 4708 bracelets; so as you see, Sarah took care of having room to loose some beads and yet the beads will be enough to make 4000 bracelets.
Of course, if you want to be sure, you should ask Sarah some questions. For example:
1) What proportion of beads are normally deffective?
2) What proportion of beads are normally lost when crafting?
So, if Sarah did not take into account those proportions she migth be overestimating the number of bracelets they can make.
Conditional probability formula is:P ( A and B ) = P ( A ) · P ( B / A )0.46 = P ( A ) · 0.31P ( A ) = 0.46 : 0.31P ( A ) = 1.48And this is impossible because 0 ≤ P ( A ) ≤ 1The student obviously made a mistake.
Answer:
D
Step-by-step explanation:
We calculate the z-score for each
Mathematically;
z-score = (x-mean)/SD
z1 = (1.9-2.1)/0.2 = -1
z2 = (2.3-2.1)/0.2 = 1
So the proportion we want to calculate is;
P(-1<x<1)
We use the standard score table for this ;
P(-1<x<1) = P(x<1) -P(x<-1) = 0.68269 which is approximately 68%
8X3 equals 24
3x 8 equals 24
Eight rows of 3 =24
3 rows of 8 = 24