The first thing we have to do is to calculate the
midpoint of the min and max speeds. We are given that the min and max is 74 and
95 respectively. The midpoint is then calculated as (max+min) / 2. Therefore:
midpoint = (74 + 95) / 2 = 84.5
Next, we calculate the distance from the midpoint to the
endpoint by doing subtraction. Therefore:
min endpoint: 84.5 – 74 = 10.5
max endpoint: 95 – 84.5 = 10.5
Now we know that v minus the midpoint will equal the
distance such that:
| v - midpoint | = distance.
To our problem,
| v – 84.5 | = 10.5
Answer:
4.5 mph or 9/2 mph
Step-by-step explanation:
Let x be the rate of the current
Formula: Distance = rate x time
where rate upstream =(12-x) and time =2 hours
15=(12-x)(2)
15=24–2x
2x=24–15
2x= 9
x=9/2=4.5 miles per hour (rate of current)
Answer:
Step-by-step explanation:
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The t distribution or Student’s t-distribution is a "probability distribution that is used to estimate population parameters when the sample size is small (n<30) or when the population variance is unknown".
The shape of the t distribution is determined by its degrees of freedom and when the degrees of freedom increase the t distirbution becomes a normal distribution approximately.
Data given
Confidence =0.99 or 99%
represent the significance level
n =16 represent the sample size
We don't know the population deviation 
Solution for the problem
For this case since we don't know the population deviation and our sample size is <30 we can't use the normal distribution. We neeed to use on this case the t distribution, first we need to calculate the degrees of freedom given by:
We know that 
so then 
and we can find on the t distribution with 15 degrees of freedom a value that accumulates 0.005 of the area on the left tail. We can use the following excel code to find it:
"=T.INV(0.005;15)" and we got 
on this case since the distribution is symmetric we know that the other critical value is 
Answer:
x=11
Step-by-step explanation:
M is the midpoint this means that we can set AM and BM equal to eachother, once this is done we can solve for x
9x-6=6x+27 (set equal to eachother)
9x=6x+33 (add 6)
3x=33 (subtract 6x)
x=11 (divide by 3)
C is the correct answer. Hope I helped :)
