Answer:
C. The electric car is not moving at 0 seconds and 12 seconds.
Step-by-step explanation:
Given:
The table given is:
x 0 2 4 6 8 10 12
y 0 45 72 81 72 45 0
From the above table, we observe that the car starts from rest and its speed increases from 0 to 6 seconds, the maximum speed being 81 mph.
After 6 seconds, the speed of the car goes on decreasing till it stops at time equal to 12 seconds.
So, the speed of the car at the start when
is 0 mph as it is at rest at that time.
Also, when the time is
, the car has come to a stop and thus its speed has reduced to 0 mph again. So, the car is not moving after 12 seconds.
From the above conclusion, we can say that only option C is correct.
The electric car is not moving at 0 seconds and 12 seconds.
Answer:
more than 15.40 cm and less than 14.60 cm
Step-by-step explanation:
A manufacturer of bolts has a quality control policy that requires it destroy any bolts that are more than 4 standard deviations from the mean.
mean length= 15 cm
standard deviation= 0.10 cm
4 standard deviation from mean= 15±(4×0.10)
therefore, bolts of length more than 15+0.4, and less than 15-0.4 will be destroyed
= 15.40 cm and 14.60 cm
Answer:

t = 2.2450
d. 0.264
Step-by-step explanation:
The null hypothesis is:

Alternative hypothesis;

The pooled variance t-Test would have been determined if the population variance are the same.



The t-test statistics can be computed as:



t = 2.2450
Degree of freedom 
df = (8-1)+(8-1)
df = 7 + 7
df = 14
At df = 14 and ∝ = 0.05;

Decision Rule: To reject the null hypothesis if the t-test is greater than the critical value.
Conclusion: We reject
and there is sufficient evidence to conclude that the test scores for contact address s less than Noncontact athletes.
To calculate r²
The percentage of the variance is;




Answer:
2
Step-by-step explanation:
X+x-17+39=180
2x+22=180
Subtract 22 from both sides
2x=158
X= 79