Answer:
66.67% probability of selecting a black marble from the bag.
Step-by-step explanation:
Initially there are 16 marbles, 10 of which are black and 6 of which are red.
A red marble is drawn and not put back. So now there are 15 marbles, of which 10 are black.
So there is a 10/15 = 2/3 = 0.666% 7 = 66.67% probability of selecting a black marble from the bag.
mu = 1100 = population mean
sigma = 275 = population standard deviation
x = 1400 = raw score
z = z score
z = (x-mu)/sigma
z = (1400-1100)/(275)
z = 300/275
z = 1.0909090909091 approximately
z = 1.09
Convention is to round to two decimal places so that you can use a Z table to look up the area under the curve (which helps determine probability).
The positive z score is due to Paula's raw score being above the mean.
Answer:
24
Step-by-step explanation:
Regroup
2(x-7)=36
Divide both sides by two
X-7= 36/2
Simplify 36/2 to 18
X-7=18
Add 7 to both sides
X=18+7
Simplify 18+7 to 25
X = 25