Replace every x in the function with a -2. 3(-2)^2 - 2(-2) + 7. Simplifying gives you 3(4) + 4 + 7. Do the math now. 12 + 4 + 7 = 23
Answer:
2.3
Step-by-step explanation:
Answer and Step-by-step explanation:
we have the following data:
Point estimate = sample mean = \ bar x = 12.39
Population standard deviation = \ sigma = 3.7
Sample size = n = 177
a) the margin of error with a 90% confidence interval
α = 1 - 90%
alpha = 1 - 0.90 = 0.10
alpha / 2 = 0.05
Z \ alpha / 2 = Z0.05 = 1,645
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 1.645 * (3.7 / \ sqrt177)
Outcome:
E = 0.46
b) margin of error with a 99% confidence interval
α = 1-99%
alpha = 1 - 0.99 = 0.01
alpha / 2 = 0.005
Z \ alpha / 2 = Z0.005 = 2,576
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 2,576 * (3.7 / \ sqrt177)
Outcome:
E = 0.72
c) A larger confidence interval value will increase the margin of error.
Answer:
- drink cost: $1.75
- slice of pizza cost: $2.25
Step-by-step explanation:
Let d and p represent the costs of a drink and a pizza slice, respectively. The two orders have a value ...
d + 3p = 8.50
2d + 2p = 8.00
Subtracting the second equation from twice the first gives ...
2(d +3p) -(2d +2p) = 2(8.50) -(8.00)
4p = 9.00 . . . . . simplify
p = 2.25 . . . . . . divide by 4
Solving the first equation for d and putting in the value, we have
d = 8.50 -3p = 8.50 -3·2.25 = 8.50 -6.75
d = 1.75
The cost of a drink is $1.75; the cost of a pizza slice is $2.25.
