Answer:
190/570
Step-by-step explanation:
190/570
8*.8=6.4
4x+6.4=40
40-6.4=33.6
33.6/4=x
8.4=x
Hope this helps :)
Answer:
By the Empirical Rule, 
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
The symbol of a standard deviation is
. So
When plotting sample statistics on a control chart, 99.7% of the sample statistic values are expected to fall within plus/minus how many sigma?
By the Empirical Rule, 
Answer to written question:
3x + 10x + 7x = 180
Combine like terms
20x = 180
Divide by 20
x = 9
Smallest angle 3x = 3*9 = 27 degrees
Answer to question in picture:
30/6x-2 = 36/5x + 13
Cross multiply
30(5x + 13) = 36(6x-2)
Distribute
150x + 390 = 216x - 72
Subtract 150x
390 = 66x - 72
Add 72
462 = 66x
Divide by 66
x = 7