move all terms to the left side and set equals to zero. then set each factor equal to zero
<em>a = 30°</em>
<em>b = 70°</em>
<em>c = 80°</em>
- Step-by-step explanation:
<em>Hi there ! </em>
<em />
<em>a ; b ; c = angles</em>
<em>a + b + c = 180°</em>
<em>b + c = 5a</em>
<em><u>replace (b + c)</u></em>
<em>a + (b + c) = 180</em>
<em>a + 5a = 180</em>
<em>6a = 180</em>
<em>a = 30°</em>
<em />
<em>b + c = 180 - a</em>
<em>b + c = 150</em>
<em>c = b + 10</em>
<em><u>replace c</u></em>
<em>b + (b + 10) = 150</em>
<em>2b = 150 - 10</em>
<em>2b = 140</em>
<em>b = 70°</em>
<em>c = b + 10</em>
<em>c = 80°</em>
<em>Good luck !</em>
Answer:
A.) The manager calculated mean and not standard deviation
B.) Standard deviation should be calculated with the use of formula.
Step-by-step explanation:
A.) The assumption that his customers do spend more than the national average is wrong because the standard deviation is not calculated and mean cannot be used as a substitute for standard deviation.
B.) Standard deviation tells us how value obtain from group measurement deviates from the average value or expected value of each item of observations.
When standard deviation is low, this show that the value is very close to the expected value or the average value.
If the national average value = $150 and average customer spends $160.
Deviation = 160 - 150 = 10
This is lower than $30
Or better still, the manager should make use of standard deviation formula. Which is the square root of variance.
