Answer:
the cyclists rode at 35 mph
Step-by-step explanation:
Assuming that the cyclists stopped, and accelerated instantaneously at the same speed than before but in opposite direction , then
distance= speed*time
since the cyclists and the train reaches the end of the tunnel at the same time and denoting L as the length of the tunnel :
time = distance covered by cyclists / speed of cyclists = distance covered by train / speed of the train
thus denoting v as the speed of the cyclists :
7/8*L / v = L / 40 mph
v = 7/8 * 40 mph = 35 mph
v= 35 mph
thus the cyclists rode at 35 mph
This infinite sum is given by
a
S = ------ but ONLY if r<1. Here, r>1, so the infinite sum does not exist.
1-r
Answer: 10 inches.
Step-by-step explanation:
We have to solve a system of equations.
The formula to calculate a triangle area is A = (b.h)/2
where b is the base and h is the height. This will be our first equation.
Since the height is 4 inches greater than the base, the second equation will be: h = b+4
We replace h and the value of the area (70 square inches) in the first equation, and we solve it by using the cuadratic equation formula:
70 = (b . (b+4)) / 2
70 . 2 = b² + 4b
140 = b² +4b
0 = b² + 4b - 140
The roots of this polynomial are -14 and 10. Since a distance can't be negative, the length of the base is 10 inches.
The volume of the case =
length x width x height
12cm x 6.5cm x 1.25cm =97.5cm^3
Answer:
1. T test for independent means
2. T test for dependent means
3. T test for dependent means
Step-by-step explanation:
In number 1, the two groups are unrelated. The first group has 25 subjects and they're all unemployed. The second group has 24 subjects and their employment status is not stated and might not be the same all through. Also, the first group is receiving a new type of job skills program while the second group is taking the standard job skills program.
- The groups in the experiment are unrelated
- The tests in the research are unrelated
- The purpose of the research is unreasonable - the researcher seeks to measure how well all 49 subjects perform on 'a' job skills test! No comparison between the scores or mean scores of the two groups.
In number 2, the researcher uses the same subjects and also measures the same variable but twice. This is a good example of a study where the t test for dependent means can be taken. Same applies in case 3.
