This is an isosceles triangle. Therefore, at the base we have congruent angles (look at the picture).
We have the equation:
(5x + 13)° + (3x + 7)° = 180°
5x + 13 + 3x + 7 = 180 <em>combine like terms</em>
(5x + 3x) + (13 + 7) = 180
8x + 20 = 180 <em>subtract 20 from both sides</em>
8x = 160 <em>divide both sides by 8</em>
<h3>x = 20</h3>
Answer:
Confidence Interval - 2.290 < S < 2.965
Step-by-step explanation:
Complete question
A chocolate chip cookie manufacturing company recorded the number of chocolate chips in a sample of 50 cookies. The mean is 23.33 and the standard deviation is 2.6. Construct a 80% confidence interval estimate of the standard deviation of the numbers of chocolate chips in all such cookies.
Solution
Given
n=50
x=23.33
s=2.6
Alpha = 1-0.80 = 0.20
X^2(a/2,n-1) = X^2(0.10, 49) = 63.17
sqrt(63.17) = 7.948
X^2(1 - a/2,n-1) = X^2(0.90, 49) = 37.69
sqrt(37.69) = 6.139
s*sqrt(n-1) = 18.2
confidence interval:
(18.2/7.948) < S < (18.2/6.139)
2.290 < S < 2.965