Answer:
The desired z-score is 2.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
n(12,2.5)
This means that 
z score when x =17
This is Z when X = 17. So



The desired z-score is 2.
Answer:

Step-by-step explanation:
Here is the complete question: 28 elementary schools to 16 middle schools, write the ratio in simplest form.
Given ratio= elementary schools: middle schools:: 28:16
The ratio can be written as 
Now to write
into simplest form, we need to divide both numerator and denominator by 4.
∴ elementary schools: middle schools= 
Hence, we get simplest ratio of elementary schools to middle schools= 
Answer:
c
Step-by-step explanation:
hope this helps
Given:
Total amount of Mingfa and her sister = $130
If Mingfa amount increased by $10, then the new amount is equal to three times of as much money as her sister.
To find:
How much money does Mingfa actually have?
Solution:
Let, Mingfa have $x and her sister has $y initially. Then,
...(i)
If Mingfa amount increased by $10, then the new amount is equal to three times of as much money as her sister.
...(ii)
Substitute the value of x from (ii) in (i).
Divide both sides by 4.
Putting
in (i), we get



Therefore, Mingfa have $95.
1/3 = 2/6 = 3/9 = 4/12 = 5/15 = 6/18 = 7/21 = 8/24 = 9/27 = 10/30 = 11/33 = 12/36 = 13/39 = 14/42 = 15/45 = 16/48 = 17/51 = 18/54 = 19/57 = 20/60
You can use any, these are just the smallest to the biggest but any are fine but I would use the first one. Hope I helped. Equivalent is what 3/9 equals to.