Answer: The point estimate for the mean weight of all spawning Chinook salmon in the Columbia River is the mean weight from your sample = 31.2 pounds .
Step-by-step explanation:
The weights of spawning Chinook salmon in the Columbia river are normally distributed.
Given : The mean weight from your sample is 31.2 pounds with a standard deviation of 4.4 pounds.
The point estimate for the mean weight of all spawning Chinook salmon in the Columbia River is the mean weight from your sample i.e. is 31.2 pounds because the best point estimate for population mean is the sample mean. [in normal distribution]
Answer:
18 gallons containing 20% solvent and 6 gallons containing 60% solvent
Step-by-step explanation:
the painter needs 24 gallons of paint containing 30% solvent = 7.2 gallons of solvent
let a = 20% solvent paint
let b = 60% solvent paint
a + b = 24
0.2a + 0.6b = 7.2
(replace a = 24 - b in the second equation)
a + b = 24
0.2(24 - b) + 0.6b = 7.2
4.8 - 0.2b + 0.6b = 7.2
0.4b = 7.2 - 4.8 = 2.4
b = 2.4 / 0.4 = 6
a = 24 - 6 = 18