Answer:628384729
Step-by-step explanation:
One two three
Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
The given problem describes a binomial distribution with p = 60% = 0.6. Given that there are 400 trials, i.e. n = 400.
a.) The mean is given by:

The standard deviation is given by:

b.) The mean means that in an experiment of 400 adult smokers, we expect on the average to get about 240 smokers who started smoking before turning 18 years.
c.) It would be unusual to observe <span>340 smokers who started smoking before turning 18 years old in a random sample of 400 adult smokers because 340 is far greater than the mean of the distribution.
340 is greater than 3 standard deviations from the mean of the distribution.</span>
Answer:
The ratio of their surface areas is 
Step-by-step explanation:
we know that
If two figures are similar, then the ratio of its corresponding sides is equal and this ratio is called the scale factor
In this problem the scale factor is equal to the ratio 
and
Remember that
If two figures are similar, then the ratio of its surface areas is equal to the scale factor squared
therefore
In this problem the ratio of their surface areas is 
Answer:
25,5 miles
Step-by-step explanation:
4.25 inch on map
4.25/0.5 = 8,5
8,5 * 3 = 25,5 miles