Answer:
Step-by-step explanation:
1) Number of white chocolate bars = x
Number of dark chocolate bars = y
Total bars = 15
x + y = 15 --------------(I)
Total cost = Php. 340
20x + 25y = 340 ----------------(II)
2) We can use elimination method to solve this equations.
Multiply equation (I) by (-20) and then add the equations.
(I)* (-20) -20x -20y = - 300
(II) <u>20x + 25y = 340 </u> {Now add and x will be eliminated}
5y = 40
y = 40/5
y = 8
Substitute y = 8 in equation (I)
x + 8 = 15
x = 15 - 8
x = 7
3) Number of dark chocolate bars = 8
Solution: We are given:

Let
be the weight (oz) of laptop
We have to find 
To find the this probability, we need to find the z score value.
The z score is given below:



Now, we have to find 
Using the standard normal table, we have:

0.9236 or 92.36% of laptops are overweight
Answer:
Stratified sampling
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.
Answer:
i have no clue but good luck
Step-by-step explanation:
We use the formula a^2 - b^2 = ( a - b )( a + b );
We have a = 5m - 2 and b = 3m - 4;
<span>(5m-2)^2-(3m-4)^2 = (5m - 2 -3m + 4) x (5m-2 + 3m - 4) = (2m + 2)(8m - 6) = 2(m +1) x 2(4m - 3) = 4(m+1)(4m-3);
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