Answer:
95% confidence interval: (0.325 ,0.383)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 231
Sample mean = 0.354 ppm
Sample standard deviation = 0.231 ppm
95% confidence interval:
Putting the values, we get,
1. 12-9×3×4+3=-93
2.3+4×3×9-12=99
3. 12-9+3×9×3×4=327
Write an equation system based on the problem
For an instance, e stands for the price of a carton of eggs, and b stands for the price of a loaf of bread
"Kate bought 3 cartons of eggs and 5 loaves of bread for $30.07" could be written as 3e + 5b = 30.07 (first equation)
"Melissa bought 2 cartons of eggs and 2 loaves of bread for $14.74" could be written as 2e + 2b = 14.74 (second equation)
Solve the equation system using elimination method
Eliminate b to find e. To eliminate b, we should equalize the coefficient of b.
3e + 5b = 30.07 (multiplied by 2)
2e + 2b = 14.74 (multiplied by 5)
-------------------------------------------
6e + 10b = 60.14
10e + 10b = 73.70
------------------------- - (substract)
-4e = -13.56
e = -13.56/-4
e = 3.39
The price for a carton of eggs is $3.39
Equilateral triangles have equal sides
117/3 = 39 mm. All the sides equal to
39 mm
Solution: 39mm
