If the speed of the stream is x
Time is given by d/r , where r is the rate and d is the distance;
Rate for upstream = (15-x) mph and that of down stream is (15 +x) mph
The time taken will be the same;
Thus; 2/(15-x) = 4/(15+x)
cross multiplying;
30 +2x = 60 -4x
6x = 30
x =5
Therefore the rate of the river is 5 mph
Answer:
b. 224
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
In this problem:
We want to find n, when 
So
The nearest integer number to 223.9 is 224.
So the correct answer is:
b. 224
In conclusion, 1,155 people went to see a comedy movie.
Answer:
a) 2.188
b) John's rent is not an outlier
c) His rent has to be higher than $1,235 to be an outlier
Step-by-step explanation:
The mean monthly rent of students at Oxnard University is $780 with a standard deviation of $208.
(a) John’s rent is $1,235. What is his standardized z-score?
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score = $1235
μ is the population mean = $780
σ is the population standard deviation = $208
Hence,
z = 1235 - 780/208
z = 2.1875
Approximately to 3 decimal place = 2.188
(b) Is John’s rent an outlier?
No it isn't
(c) How high would the rent have to be to qualify as an outlier?
John’s rent would have to be higher than $1235
Answer:
Slope (m)
-0.2222
m = 2 / -9 = -0.222
Step-by-step explanation:
