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
Answer:
Z scores between -0.995 and 0.995 bound the middle 68% of the area under the stanrard normal curve
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.
Middle 68%
Between the 50 - (68/2) = 16th percentile and the 50 + (68/2) = 84th percentile.
16th percentile:
X when Z has a pvalue of 0.16. So X when Z = -0.995
84th percentile:
X when Z has a pvalue of 0.84. So X when Z = 0.995.
Z scores between -0.995 and 0.995 bound the middle 68% of the area under the stanrard normal curve