Difference of 2 perfect squares
a^2-b^2=(a-b)(a+b)
recognize that
(2x+1)(2x-1)
(a+b)(a-b)
therefor
product is
(2x)^2-(1)^2=
4x^2-1
Answer:
75/4=3/100
Step-by-step explanation:
sinple this is on proportion
if you want crisscross the fraction
Answer: 78
Step-by-step explanation: Remember every triangle ads up to a total of 180 degrees. You just have to make sure that it adds up to 180
Answer:
149/60
Step-by-step explanation:
11/4-27/8*1/4*1/2
11/4-27/64
149/64
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