Answer:
B C E
Step-by-step explanation:
Read the question
Answer:
Check the explanation
Step-by-step explanation:
Here we have to first of all carry out dependent sample t test. consequently wore goggles first was selected at random for the reason that the reaction time in an emergency taken with goggles would be greater than the amount of reaction time in an emergency taken with not so weakened vision. So that we will get the positive differences d = impaired - normal
b)
To find 95% confidence interval first we need to find sample mean and sample sd for difference d = impaired minus normal.
We can find it using excel that is in the first attached image below,
Therefore sample mean
= 0.98
Sample sd
= 0.3788
To find 95% Confidence interval we can use TI-84 calculator,
Press STAT ----> Scroll to TESTS ---- > Scroll down to 8: T Interval and hit enter.
Kindly check the attached image below.
Therefore we are 95% confident that mean difference in braking time with impaired vision and normal vision is between ( 0.6888 , 1.2712)
Conclusion : As both values in the interval are greater than 0 , mean difference impaired minus normal is not equal to 0
There is significant evidence that there is a difference in braking time with impaired vision and normal vision at 95% confidence level .
Answer:
11 hours she worked at the grocery store
Step-by-step explanation:
assuming,
the number of hours worked at tutoring = x
the number of hours worked at grocery store = y
which means,
the amount she made at tutoring = x* $15
the amount she made at grocery store = y*$9
we have 2 equations
<em>total number of hours</em>
1) x+y= 15
<em>total amount she earned</em>
2) x* $15+ y* $9= $159
From equation 1
x+y= 15
x=15-y
<em>we replace this x value in equation 2</em>
x* $15+ y* $9= $159
(15-y)* $15+ y* $9= $159
(15*15)- 15y+9y=159
225-6y=159
225-159=6y
66=6y
66/6=y
<u>11=y</u> <em>the number of hours she worked at grocery store. </em>
<em>we place y=11 in our derived x equation</em>
x=15-y
x=15-11
<u><em>x=4 </em></u><em>the number of hours she worked at tutoring. </em>
Answer:
(x - 4) to the second power
Step-by-step explanation:
Answer:
they work together, it will take 2.4 hours to build the wall.
Step-by-step explanation:
One bricklayer can build a wall in 6 hours.
One hour work = 
Another bricklayer can build the same wall in 4 hours.
One hour work = 
They can together, how long will take them to build the wall.
Let's take "t" the time taken to build the wall.
The sum of their work rate = 1 (To build the wall)

Now we have to solve this equation. Take LCD of 6 and 4.
The LCD (least common divisor) of 6 and 4 is 12.

5t = 12*1
5t = 12
Dividing both sides by 5, we get
t = 
t = 2.4 hours.
So, they work together, it will take 2.4 hours to build the wall.