Answer:
D
Step-by-step explanation:
r = boat's rate
c = current's rate
1. A boat traveled in a river upstream for a distance of 30 miles. Travelling upstream, the current obstructs the movement, so the actual boat's rate is r - c mph.
If the boat took 4 hours to travel upstream, then
2. A boat traveled in a river downstream for a distance of 30 miles. Travelling downstream, the current helps the movement, so the actual boat's rate is r + c mph.
If the boat took 3 hours to travel downstream, then
So, we get the system
4r-4c=30
3r+3c=30
Answer:
Comparing means from dependent samples.
Step-by-step explanation:
In the scenario described above, the 25 sampled individuals were used to test the effect of weightlifting on alleviating back pain. The samples used were not changed nor altered during the study as the same subjects who were tested to measure their level of pain before lifting weight were the same group subjected to the actual weight lifting test and again had their level of pain tested. Since only one group was involved in the study ( a single group was tested on neutral and actual treatment). Hence, the study used dependent samples to compare the average level of pain.
No they are not the the same. 3/2 = 1.5 and 3/4 = .75
There are 22 fourths in 5 1/2
