15h > = 200
h > 200/15
h > 13 1/3.......1/3(60) = 60/3 = 20
13 hrs and 20 minutes is correct...nice job :)
The GRE Scores are represented as ~N(310,12)
In order to find the proportion of scores between 286 and 322, we need to standardize the scores so we can use the standard normal probabilities. Thus, we will find the z-score.
By looking on the standard normal probabilities table, we find the proportion of scores less than -2.
P(z < -2) = 0.0228
Then, we find the proportion of scores less than 1.
P(z < 1) = 0.8413
To find the proportion between -2 and 1, we subtract the two.
P(-2 < z < 1) = 0.8413 - 0.0228 = 0.8185 = 81.85%
Therefore, 82% of scores are between 286 and 322
Answer:
Step-by-step explanation:
Answer
39 bills of 1$
16 bills of 10$
Step-by-step explanation:
x-nr of $1
y-nr of $10
x*1+y*10=199
x+y=55 , x=55-y
so I use the substitution method
(55-y)*1+10y=199
55+10y-y=199
-55 -55
9y=144
y=144/9
y=16
so x=55-16
x=39
verify 16*10+39*1=160+39=199
X = 4, You subtract the 5x to the other side then divide the 32 by 8 to get 4.