Answer:
Step-by-step explanation:
Let b
Bill's rate of travel = x
Let Julie's rate of travel = 3x
The time each travels is 2.5 hours
Together they travel a distance of 190 miles
d = r*t
Bill's distance covered is r * t = 2.5x
Julie's distance travel is 2.5 * 3x = 7.5x
The total distance = Bill + Julie
2.5x + 7.5x = 190
10x = 190
x = 190/10
x = 19
Bill's distance = 2.5 * 19 = 47.5
Julie's distance = 19 * 7.5 = 142.5
Rate = distance / time
Bill's rate = 47.5 / 2.5 = 19 miles per hour.
Julie's rate = 142.5/2.5 = 57 miles per hour
Is there an easier way?
You should notice that Bill's rate is just x which is 19 miles / hour
You can also notice that Julie is going 3 times as fast or 19*3 = 57
The answer is 140, you just add them up and it goes by 2.
The inverse of function f(x) = 9x+7 is f-1(x) = x/9 - 7/9
<h3>How to determine the inverse of the function?</h3>
The function is given as:
f(x) = 9x + 7
Express f(x) as y
y = 9x + 7
Swap the positions of x and y in the above equation
x = 9y + 7
Subtract 7 from both sides
9y = x - 7
Divide through by 9
y = x/9 - 7/9
Express as an inverse function
f-1(x) = x/9 - 7/9
Hence, the inverse of function f(x) = 9x+7 is f-1(x) = x/9 - 7/9
Read more about inverse functions at:
brainly.com/question/14391067
#SPJ1
25/28
is in it's lowest form, as it cannot be reduced anymore.
25/28 = 0.8928571
hope this helps
Answer:
the probability that five randomly selected students will have a mean score that is greater than the mean achieved by the students = 0.0096
Step-by-step explanation:
From the five randomly selected students ; 160, 175, 163, 149, 153
mean average of the students = 160+175+163+149+153/5
= mean = x-bar = 800/5
mean x-bar = 160
from probability distribution, P(x-bar > 160) = P[ x-bar - miu / SD > 160 -150.8 /3.94]
P( Z>2.34) = from normal Z-distribution table
= 0.0096419
= 0.0096
hence the probability that five randomly selected students will have a mean score that is greater than the mean achieved by the students = 0.0096
where SD = standard deviation = 3.94 and Miu = 150.8
