Answer:
There is significant evidence to conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
Step-by-step explanation:
Given the data :
6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7
The hypothesis:
H0: μ = 3.2
H1 : μ > 3.2
n = sample size = 12
The sample mean, xbar = ΣX / n
xbar = 53.2 / 12
xbar = 4.43
Using calculator;
Sample standard deviation, s = 2.147
The test statistic :
(xbar - μ) ÷ (s/sqrt(n))
(4.43 - 3.2) ÷ (2.147/sqrt(12)
1.23 / 0.6197855
Test statistic = 1.985
The Pvalue using the Pvalue from Tscore calculator :
Tscore = 1.985 ; df = 12 - 1 = 11
Pvalue = 0.036
Since Pvalue < α ; We reject the Null
Hence, we conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.
Answer:
2.5 sec
Step-by-step explanation:
Height of wall = 2.5 m
initial speed of ball = 14 m/s
height from which ball is kicked = 0.4 m
we calculate the speed of the ball at the height that matches the wall first
height that matches wall = 2.5 - 0.4 = 2.1 m
using = + 2as
where a = acceleration due to gravity = -9.81 m/s^2 (negative in upwards movement)
= + 2(-9.81 x 2.1)
= 196 - 41.202
= 154.8
v = = 12.44 m/s
this is the velocity of the ball at exactly the point where the wall ends.
At the maximum height, the speed of the ball becomes zero
therefore,
u = 12.44 m/s
v = 0 m/s
a = -9.81 m/s^2
t = ?
using V = U + at
0 = 12.44 - 9.81t
-12.44 = -9.81
t = -12.44/-9.81
t = 1.27 s
the maximum height the ball reaches will be gotten with
= + 2as
a = -9.81 m/s^2
0 = + 2(-9.81s)
0 = 196 - 19.62s
s = -196/-19.62 = 9.99 m. This the maximum height reached by the ball.
height from maximum height to height of ball = 9.99 - 2.5 = 7.49 m
we calculate for the time taken for the ball to travel down this height
a = 9.81 m/s^2 (positive in downwards movement)
u = 0
s = 7.49 m
using s = ut + a
7.49 = (0 x t) + (9.81 x )
7.49 = 0 + 4.9
= 7.49/4.9 = 1.53
t = = 1.23 sec
Total time spent above wall = 1.27 s + 1.23 s = 2.5 sec
Answer:
x = 5
Step-by-step explanation:
= 19 - x = 14
= 19 - x - 19 = 14 - 19
= -x = -5
= -x/-1 = -5/-1x
x = 5
Hope this Helps :D
To answer this, we need the original equation.
