To determine the average water use, 109 people must be sampled.
1.9 gallons is the standard deviation.
E = 0.15 gallons maximum error
1.9 gallons on average
90% is the critical value.
1.645 is the 90% confidence interval.
sample size requirement,
n = (((z ÷ 2) × σ) ÷ E)²
n = (((1.645 ÷ 2) × 1.9) ÷ 0.15)²
n = ((0.8225 × 1.9) ÷ 0.15)²
n = (1.5627 ÷ 0.15)²
n = (10.418)²
n = 108.53 ≈ 109
As a result, the minimal sample size necessary to determine the mean water use = 109.
It is determined by dividing the average standard error by the squared of the sample size, and it decreases with increasing sample size. In other words, when the sample size is sufficiently big, the population mean approaches the population mean.
To learn more about the sample interval at
brainly.com/question/13664567?referrer=searchResults
#SPJ4
Answer:
What's your question?
Step-by-step explanation:
Answer:
Step-by-step explanation:
For Question 3, we are simply taking an input for the function, as a value of x and solving the equation. For part a, we substitute 3/14 into the first function, and solve it:
f(x) = 7(3/14) + 2
f(x) = 21/14 + 2
f(x) = 49/14
f(x) = 7/2
For part b, we take the input of -3 into the second function and solve the equation:
h(x) = 4(-3)^2
h(x) = 4(9)
h(x) = 36
For Question 4, we are simply solving this equation by isolating the x variable. First, we simplify the equation to 4-5x+15+2x = -2 and simplify this again to -3x+19 = -2. Now, we can subtract 19 from both sides of the equation to get -3x = -21. Lastly, we isolate the x variable by dividing both sides of this equation by -3, to get x = 7.
Answer:
I think it is 24
Step-by-step explanation:
15÷5=3
3×8=24
