Answer:
Due to the higher z-score, Jane did better in class.
Step-by-step explanation:
Z-score:
In a set with mean 
and standard deviation 
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this question:
Whoever's grade had the better z-score did better in class.
Mary's:
Mean of 85, standard deviation of 5, grade of 88. This means that 
. So
Jane's
Mean of 80, standard deviation of 10, grade of 88. This means that 
. So
Due to the higher z-score, Jane did better in class.
Answer:
Step-by-step explanation:
Model the expressions
with bar models or algebra tiles to determine if the expressions are
Equivalent.
You can also write equivalent expressions using
properties of operations
and order of operations.
The ground level is to be the zero level. When the elevator moves above the ground level, it is moving towards the positive integer and when the elevator moves below the ground level, it is moving towards the negative integer.
Elevator 2 moved down 6 feet from the ground level hence its position is labelled as
Since there is no repetition allowed, there are 10 possibilities for the 1st digit, 9 for the 2nd, 8 for the 3rd, and 7 for the 4th. This gives a total of (10)(9)(8)(7) = 5040 four-digit codes.
For all odd digits to be used, there are 5 possibilities for the 1st digit (1,3,5,7,9), 4 for the 2nd, 3 for the 3rd, 2 for the 4th. This gives a total of (5)(4)(3)(2) = 120 codes that only use odd digits.
Therefore there are 5040 - 120 = 4920 codes that do not consist of all odd digits. The probability is 4920/5040 = 41/42.
We can solve this by setting up 2 equations. We can use any letters like. For now, I'll use x and y.
So now we know that x - y = 0.7 and x + y = 1.
Now we can eliminate one of the letters by adding or subtracting one equation from the other. I am going to eliminate y by adding the two together (the y and the -y cancel).
This gives us 2x = 1.7, and so x = 1.7 ÷ 2 = 0.85
Finally, we can substitute x for 0.85 back into one of the original equations to figure out what y equals. I'm going to use x + y = 1.
So now we have 0.85 + y = 1, so y = 1 - 0.85 = 0.15
The numbers, therefore, are 0.85 and 0.15 (you can check by using the other equation).
Hope this helps!
