7x=-2x+27 add two x to both sides to isolate the x based on the addition property of equality
9x=27 divide the two sides by nine based on the division property of equality
x=3 this is your answer
Okay so finding the difference of 19 and 13.30, 5.70 is what we need to find when we start finding the sale percentage.
19*.15 = 2.85 (Too small!)
19*.25 = 4.75 (Not quite)
19*.30 = 5.70 (Bingo!)
The percentage off is 30%
Answer: Dude, the answer is 1/4.
Step-by-step explanation: 1 whole - 3/4 =1/4
Answer:
Samantha's grade was 1.29 standard deviations above the class mean, that is, she scored better than 0.9015 = 90.15% of the class.
Step-by-step explanation:
Z-score:
In a set with mean
and standard deviation
, the z-score of a measure X is given by:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
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.
In this question:
She scored better a proportion of the class given by the p-value of z = 1.29
z = 1.29 has a p-value of 0.9015.
Samantha's grade was 1.29 standard deviations above the class mean, that is, she scored better than 0.9015 = 90.15% of the class.