Answer:
c. -1
b. 5
Step-by-step explanation:
x^2 - 4x - 5 = 0
Factor
What two numbers multiply to -5 and add to -1
-5*1 = -5
-5+1 = -4
(x-5) (x+1) =0
Using the zero product property
x-5 =0 x+1 =0
x=5 x=-1
Answer:
a) 0.04
b) 0.08
Step-by-step explanation:
Part a)
Divide the price of a pack by the number of stickers in a pack to get the price of one sticker.
$2/50 = $0.04/1
One stickers costs $0.04.
Part b)
Calculate 80% more than the price of one sticker.
80% in decimal form is 0.8. 80% more than the price is calculated with the factor 1.8.
($0.04)(1.8) = $0.072
Round 0.072 up because is rounded down, the profit is less than 80%.
0.072 => 0.08
Each sticker would need to be sold for $0.08.
Answer:
H0: μ = 5 versus Ha: μ < 5.
Step-by-step explanation:
Given:
μ = true average radioactivity level(picocuries per liter)
5 pCi/L = dividing line between safe and unsafe water
The recommended test here is to test the null hypothesis, H0: μ = 5 against the alternative hypothesis Ha: μ < 5.
A type I error, is an error where the null hypothesis, H0 is rejected when it is true.
We know type I error can be controlled, so safer option which is to test H0: μ = 5 vs Ha: μ < 5 is recommended.
Here, a type I error involves declaring the water is safe when it is not safe. A test which ensures that this error is highly unlikely is desirable because this is a very serious error. We prefer that the most serious error be a type I error because it can be explicitly controlled.
Answer:
first one
Step-by-step explanation: