you divide 72 by 2 to get r by itself and get 36
so r=36
Step-by-step explanation:
1.
2.
3.
- 485 - 319 = 166 more people
4.
- 14.5x + 80 > 500
- 14.5x > 420
- x > 420/14.5
- x > 29
5.
- 1.25x + 3 ≤ 28
- 1.25x ≤ 25
- x ≤ 25/1.25
- x ≤ 20 miles
6. <em>This seems a typo... 460 is likely $60</em>
- 60x + 145 ≤ 625
- 60x ≤ 625 - 145
- 60x ≤ 480
- x ≤ 480/60
- x ≤ 8 days
A^2 + b^2 = c^2
8^2 + 15^2 = 17^2
64 + 225 = 289
289=289
It is a triangle because the numbers match the Pythagorean Theorem.
Answer:
71.123 mph ≤ μ ≤ 77.277 mph
Step-by-step explanation:
Taking into account that the speed of all cars traveling on this highway have a normal distribution and we can only know the mean and the standard deviation of the sample, the confidence interval for the mean is calculated as:
≤ μ ≤ 
Where m is the mean of the sample, s is the standard deviation of the sample, n is the size of the sample, μ is the mean speed of all cars, and
is the number for t-student distribution where a/2 is the amount of area in one tail and n-1 are the degrees of freedom.
the mean and the standard deviation of the sample are equal to 74.2 and 5.3083 respectively, the size of the sample is 10, the distribution t- student has 9 degrees of freedom and the value of a is 10%.
So, if we replace m by 74.2, s by 5.3083, n by 10 and
by 1.8331, we get that the 90% confidence interval for the mean speed is:
≤ μ ≤ 
74.2 - 3.077 ≤ μ ≤ 74.2 + 3.077
71.123 ≤ μ ≤ 77.277