Answer:
7.83 km/h
Step-by-step explanation:
Let v = average speed for first part, v' = average speed for second part.
Given that v' = v - 15, the distance covered by the first part d = 350 km. The distance covered in the second part d' = 470 km - 350 km = 120 km.
Since both parts are covered in the same time,
d = vt and d' = v't = (v - 15)t
So, 350 = vt (1) and 120 = vt - 15t (2)
substituting vt = 350 into (2), we have
120 = 350 - 15t
collecting like terms, we have
15t = 350 - 120
simplifying, we have
15t = 230
dividing through by 15, we have
t = 230/15
t = 15.33 h
Since d' = v't, then
v' = d'/t
= 120 km/15.33 h
= 7.83 km/h
So, the average speed for the second part of the journey is 7.83 km/h
A. $8.80
5.60+4.10=9.70 so 18.50-9.7=8.80
Answer:
°
Step-by-step explanation:
Answer:
the 90% confidence interval is ( 48.684 , 51.316 )
Step-by-step explanation:
Given that :
the sample size = 36
Sample Mean = 50
standard deviation = 4.80
The objective is to calculate a 90% confidence interval.
At 90% confidence interval ;
the level of significance = 1 - 0.9 = 0.1
The critical value for
= 1.645
The standard error S.E =
=
= 0.8
The Confidence interval level can be computed as:
For the lower limit :
=50 - 1.316
= 48.684
For the upper limit :
=50 + 1.316
= 51.316
Thus, the 90% confidence interval is ( 48.684 , 51.316 )
First, let's prove that triangle ABC and AFG are similar.
Line segment FG and BC are parallel to each other, that's a given.
With this information, we can state that these sides are similar to each other since you can transform BC on to FG using only rigid transformations and dilations.
Another thing is that both of these triangles share angle A, that's a given. Therefore, using the SA similar theorem, we can conclude that these triangles are similar.
Now that we know that triangle ABC and AFG are similar we may start going to the answer box.
We can eliminate the first three answer choices for having sides we cannot make full conclusions due to limited knowledge.
The only answer remaining is the fourth choice.