Answer:
The answer is 0.9599.
Explanation:
mu (sample) = mu = 8.4
s.d. (sample) = 1.8/ sq. rt. 40
P( greater than 8.1) = (8.9-8.4)/(1.8/ sq. rt. 40)
Let x be the mean time for the 40 mechanics
Standardize the mechanics: (8.9-8.4)/(1.8/ sq. rt. 40) = 1.75 = Z
P( x > 8.9) = P(Z > 1.75), this means the area to the right of Z = 1.75.
Then you need to look in the table of the Normal distribution, Z(1.75) =0.9599
Answer:
Explanation:
The time when they meet is t in hours
The general formula for both cars is d = r*t
t is unknown
r1 = 55 mph
r2 = 60 mph
60 mph * t + 55 mph*t = 100 miles
t * (60 mph + 55 mph) = 100 miles
t * 115 = 100 miles
t = 100 miles / 115 mph
t = 0.8696 hours
1 hour has 60 minutes
0.8696 hour = x
x = 0.8696 hours * 60
x = 52 minutes and 10 seconds
They will meet at 2:52:10
You have to give answers to get the time to agree.
You're starting with
(12.0 mL) (0.550 M) = (0.0120 L) (0.550 M) = 0.00660 mol
of FeCl₃.
For every mole of FeCl₃ in the balanced reaction, you need 3 moles of NH₄OH, so you need a minimum 0.0198 mol NH₄OH per mole FeCl₃.
Then the requisite volume of NH₄OH solution needed is <em>V</em> such that
(0.0198 mol) / <em>V</em> = 0.200 M
Solve for <em>V</em> to get
<em>V</em> = (0.0198 mol) / (0.200 M) = 0.0990 L = 99 mL
