Answer:
Amy has 12 5¢ coins
Step-by-step explanation:
Let <em>x</em> represent 20¢ coins and <em>y</em> represent 5¢ coins.
Amy has four more 20¢ coins than 5¢ coins. Hence:
And the total value of all her coins is $3.80. Thus:
This yields a system of equations:
We can solve by substitution. Substitute the first equation into the first:
Distribute:
Combine like terms:
And divide both sides by 0.25. Hence:
Thus, Amy has 12 5¢ coins.
Using the first equation:
Substitute:
Thus, Amy has 16 20¢ coins.
In conclusion, Amy has 12 5¢ coins and 16 20¢ coins.
Answer:
It would be absolute value I think :)
Y=6x+4
Blanks from left to right:
-14,-2,10,22,6x+4
Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)
Answer:
Step-by-step explanation:
Craig left his house at noon and drove 50 miles per hour until 3PM. Then he drove the next 5 hours at 70 miles per hour. Calculate the average rate of change for the entire trip.
