Z-score for 30 = (30 - 25) / 5.8 = 0.8621
z-score for 20 = (20 - 25) / 5.8 = -0.8621
:
Note find probabilities from z-tables
:
Probability ( 20 < X < 30 ) = 0.8051 - 0.1949 = 0.6102
We will get the number of possible selections, and then subtract the number less than 25 cents.
We can choose the number of dimes 5 ways 0,1,2,3 or 4.
We can choose the number of nickels 4 ways 0,1,2 or 3.
We can choose the number of quarters 3 ways 0,1, or 2.
That's 5*4*3 = 60 selections
Now we must subtract from the 60 the number of selections of coins that are less than 25 cents. These will involve only dimes and nickels.
To get a selection of coin worth less than 25 cents:
If we use no dimes, we can use 0,1,2 on all 3 nickels.
That's 4 selections less than 25 cents. (that includes the choice of No coins at all in the 60, which we must subtract).
If we use exactly 1 dime , we can use 0,1,2, or all 3 nickels.
That's the 3 combinations less than 25 cents.
And there is 1 other selection less than 25 cents, 2 dimes and no nickels.
So that's 4+3+1 = 8 selections which we must subtract from the 60.
Answer 60-8 = 52 selections of coins worth 25 cents or more.
Answer:
269.1
Step-by-step explanation:
We are given
△ABC, m∠A=60° m∠C=45°, AB=8
Firstly, we will find all angles and sides
Calculation of angle B:
we know that sum of all angles is 180
m∠A+ m∠B+m∠C=180
we can plug values
60°+ m∠B+45°=180
m∠B=75°
Calculation of BC:
we can use law of sines
now, we can plug values
Calculation of AC:
now, we can plug values
Perimeter:
we can plug values
Area:
we can use formula
now, we can plug values
...............Answer
