Answer:
Every 30 hours
Step-by-step explanation:
Train A arrives at central station on the hour and every 12 minutes, you mean with that on every 72 minutes
Train B arrives at central station on the hour and every 15 minutes, you mean with that on every 75 minutes
In accordance with the given, the smallest number containing numbers 72 and 75 is 1800 minutes.
When we convert this number of minutes in hours we get:
1800 / 60 = 30 hours
God with you!!!
Cross multiply: 60%/100% =21/x
X is the variable we are trying to find.
100*21=2,100
2,100/60
X =35
All together in the choir there are 35 members.
I hope this helps!
Answer:
f(x) = 4x² + 48x + 149
Step-by-step explanation:
f(x) = 4(x + 6)^2+ 5 Distribute
f(x) = 4x² + 48x + 144 + 5 Combine like terms
f(x) = 4x² + 48x + 149
Answer:
We can conclude the mean cost is larger for adopting children from Russia.
Step-by-step explanation:
To answer this question we can perform an hypothesis testing on the differences of the means with the following null and alternative hypothesis:
The significance level we assume is 0.05.
First we calculate the mean standard error:
The harmonic mean of the sample sizes is:
Then we can calculate the estimated standard deviation as:
The t-statistic can be calculated as:
The degrees of freedom are .
We can look up the P-value in a table or applet. For t=-4.015 and df=32, the P-value is 0.00017.
The P-value is smaller than the significance level, so the effect is significant and the null hyphotesis (China cost is equal or less than in Russia) is rejected.
We can conclude the mean cost is larger for adopting children from Russia.