Billy has a $40 gift card. She spends $10 per week. Write a linear equation for this situation.
1 answer:
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Answer:
A score of 150.25 is necessary to reach the 75th percentile.
Step-by-step explanation:
Problems of normal distributions can be solved using the z-score formula.
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.
A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30.
This means that
What score is necessary to reach the 75th percentile?
This is X when Z has a pvalue of 0.75, so X when Z = 0.675.
A score of 150.25 is necessary to reach the 75th percentile.
Answer:
.
Step-by-step explanation:
The given equation is
Using distributive property, we get
Isolate variable terms.
Divide both sides by -0.35.
Therefore, .
Answer:
x=1, y=-5
Step-by-step explanation:
Given equations are:
In order to solve the equation
Multiplying Eqn 1 by 5 and eqn 2 by 3 and subtracting them
So,
Eqn 1 becomes
15x+50y=-235
Eqn 2 becomes
15x-21y=120
Subtracting 2 from a
15x+50y - (15x-21y) = -235-120
15x+50y-15x + 21y = -355
71y = -355
y = -355/71
y =-5
Putting y= -5 in eqn 1
3x+10(-5) = -47
3x -50 = -47
3x = -47+50
3x = 3
x = 3/3
x = 1
Hence the solution is:
x=1, y=-5