Answer:
Step-by-step explanation:
If all 21 coins were dimes, she'd have $2.10. But she has 90 more cents than that. Now for each coin that's a quarter, not a dime, she has 15 cents more. 90/15= 6. So there are 6 quarters, and 21-6 = 15 dimes.
Now we do it backwards to see if it's right. 6 quarters is $1.50, 15 dimes is $1.50, add those together and you get $3. So it's right. 6 quarters, 15 dimes.
Answer:
The copy machine makes 87.5 copies in one minute.
Step-by-step explanation:
Set up an equation to divide 4 into 350. This is because in order to know how many copies is being made in 1 minute, you need to determine the rate of copies per minute.
350 divided by 4 is 87.5.
4y=-20+3x and 4y=13.6x-20
so
-20+3x=13.6x-20
3x=13.6x
3=13.6 so it is wrong and system doesn’t have solution
Answer:
We accept H₀ , we do not have enought evidence for rejecting H₀
Step-by-step explanation:
Normal Distribution
sample size n = 60
standard deviation σ = 15
1.Hypothesis Test : Is a one tailed-test on the right
H₀ null hypothesis μ₀ = 50
Hₐ alternative hypothesis μ₀ > 50
2.-We will do the test for a significance level α = 0,01 tht means for a 99% interval of confidence
then z(c) = 2.32
3.- We compute z(s)
z(s) = [ ( μ - μ₀ ) /( σ/√n ) ⇒ z(s) = ( 2 * √60 ) / 15
z(s) = 15.49/15 ⇒ z(s) = 1.033
4.- We compare values of z(c) and z(s)
z(s) < z(c) 1.033 < 2.32
z(s) is in the acceptance region so we accept H₀ , we do not have enough evidence for rejecting H₀
