Step-by-step explanation:Let number of 49 cents =A
Let number of 33 cents=B
<u>A+B=45 equation 1</u>
1 $=100 cents
49 cents =.49 dollar
33 cents=.33 dollar
so .<u>49A+.33B=17.89 equation 2</u>
Add equation 1 and equation 2
since these are simultaneous equations
.49A+.33B=17.89
A+ B=45
so divide equation 2 by 100 we get
49A+33B=1789
A+B =45 multiply equation 1 by 33 on both the sides we get
<u>33A+33B=1485 equation 3</u>
so subtract equation 3 from equation 2 we get
49A+33B=1789 equation 2
<u>33A+33B=1485 equation 3</u>
<u>16A+0 =304</u>
16A=304
A=304/16
A=19
putting nalue of A in equation 1 we get
A+B=45
19+B=45
B=45-19
B=26
so number of 49 cent stamps are 19
and number of 33 cent stamps are 26
Answer: put the parallelograms in the box that says 2 pairs of parallel sides next put the squares in the box that says 4 right angles the put rectangles in the box that says 4 congruent sides and last put rhombuses in the middle box that says 4 right angles and 4 congruent sides
Step-by-step explanation:
Answer:
Rhombus
Step-by-step explanation:
Let 
be the total amount of money paid by any given set of passengers. If there are 
passengers in a car, then the driver must pay a toll of 
.
Then has first moment (equal to the mean)
![E[Y]=E[0.5X+3]=0.5E[X]+3E[1]=0.5\mu_X+3=\boxed{4.35}](https://tex.z-dn.net/?f=E%5BY%5D%3DE%5B0.5X%2B3%5D%3D0.5E%5BX%5D%2B3E%5B1%5D%3D0.5%5Cmu_X%2B3%3D%5Cboxed%7B4.35%7D)
and second moment
![E[Y^2]=E[0.25X^2+3X+9]=0.25E[X^2]+3E[X]+9E[1]=0.25E[X^2]+3\mu_X+9](https://tex.z-dn.net/?f=E%5BY%5E2%5D%3DE%5B0.25X%5E2%2B3X%2B9%5D%3D0.25E%5BX%5E2%5D%2B3E%5BX%5D%2B9E%5B1%5D%3D0.25E%5BX%5E2%5D%2B3%5Cmu_X%2B9)
Recall that the variance is the difference between the first two moments:
![\mathrm{Var}[X]=E[X^2]-E[X]^2\implies E[X^2]={\sigma^2}_X+{\mu_X}^2](https://tex.z-dn.net/?f=%5Cmathrm%7BVar%7D%5BX%5D%3DE%5BX%5E2%5D-E%5BX%5D%5E2%5Cimplies%20E%5BX%5E2%5D%3D%7B%5Csigma%5E2%7D_X%2B%7B%5Cmu_X%7D%5E2)
![\implies E[Y^2]=0.25({\sigma^2}_X+{\mu_X}^2)+3\mu_X+9\approx19.22](https://tex.z-dn.net/?f=%5Cimplies%20E%5BY%5E2%5D%3D0.25%28%7B%5Csigma%5E2%7D_X%2B%7B%5Cmu_X%7D%5E2%29%2B3%5Cmu_X%2B9%5Capprox19.22)
![\implies\mathrm{Var}[Y]=E[Y^2]-E[Y]^2=\boxed{0.3}](https://tex.z-dn.net/?f=%5Cimplies%5Cmathrm%7BVar%7D%5BY%5D%3DE%5BY%5E2%5D-E%5BY%5D%5E2%3D%5Cboxed%7B0.3%7D)
