Answer:
The correct option is 1.148 < σ < 6.015
Explanation:
The 99% confidence interval for the standard deviation is given below:
Where:
Therefore, the 99% confidence interval is:
Therefore, the option 1.148 < σ < 6.015 is correct
Answer:
The volume of the solution with 20% acid is 27 gallons and the one with 10% acid is 18 gallons
Step-by-step explanation:
Myra needs to mix "x" gallons of the solution with 20% and "y" gallons of the solution with 10%. The volume of the final solution must be 45 gallons, therefore:
x + y = 45
The concentration of acid of the final solution is:
0.2*x + 0.1*y = 45*0.16
0.2*x + 0.1*y = 7.2
Therefore we have a system of equation:
x + y = 45
0.2*x + 0.1*y = 7.2
We need to multiply the first equation by -0.1:
-0.1*x -0.1*y = -4.5
0.2*x + 0.1*y = 7.2
We now sum both equation:
0.1*x = 2.7
x = 2.7/0.1 = 27 gallons
y = 45 - 27 = 18 gallons
Answer:0,1,2
Step-by-step explanation:every x
Let the letter o represent the original price.
17.85 = o + (o*1.10)
17.85 = 2.10 * o
o = 17.85/2.10=8.5
The original price was $8.50
