Answer:
4.4 inches
Step-by-step explanation:
Here, we are interested in calculating the value of x.
Mathematically, a line that comes from the center of the circle and extends to a chord, divides the chord into two equal parts.
This means what we have is a right angled triangle with the radius being the hypotenuse, the half of the length of the chord as the other side of the triangle.
3.7 is half the length of the chord i.e 7.4/2
Thus;
using Pythagoras’ theorem
x^2 = 2.4^2 + 3.7^2
Pythagoras’ posited that the square of the hypotenuse is equal to the sum of the squares of the other two sides of the triangle.
Thus;
x^2 =5.76 + 13.69
x^2 = 19.45
x = √(19.45)
x = 4.41 inches which is 4.4 inches to the nearest tenth
Part a), solve this system of equations:
x + y = 5
x - y = 2.25
2x = 7.25
x = 3.625
y = 1.375
part b), solve this system of equations:
x + y = 5
x = 3y
y = 1.25
x = 3.75
Let
denote the value on the
-th drawn ball. We want to find the expectation of
, which by linearity of expectation is
![E[S]=E\left[\displaystyle\sum_{i=1}^5B_i\right]=\sum_{i=1}^5E[B_i]](https://tex.z-dn.net/?f=E%5BS%5D%3DE%5Cleft%5B%5Cdisplaystyle%5Csum_%7Bi%3D1%7D%5E5B_i%5Cright%5D%3D%5Csum_%7Bi%3D1%7D%5E5E%5BB_i%5D)
(which is true regardless of whether the
are independent!)
At any point, the value on any drawn ball is uniformly distributed between the integers from 1 to 10, so that each value has a 1/10 probability of getting drawn, i.e.

and so
![E[X_i]=\displaystyle\sum_{i=1}^{10}x\,P(X_i=x)=\frac1{10}\frac{10(10+1)}2=5.5](https://tex.z-dn.net/?f=E%5BX_i%5D%3D%5Cdisplaystyle%5Csum_%7Bi%3D1%7D%5E%7B10%7Dx%5C%2CP%28X_i%3Dx%29%3D%5Cfrac1%7B10%7D%5Cfrac%7B10%2810%2B1%29%7D2%3D5.5)
Then the expected value of the total is
![E[S]=5(5.5)=\boxed{27.5}](https://tex.z-dn.net/?f=E%5BS%5D%3D5%285.5%29%3D%5Cboxed%7B27.5%7D)
The rate of change is -2 :)
1 hr 18 minutes and 27 seconds hmmm
there are 60 minutes in 1 hr, thus 18 minutes is 18/60 hrs or 0.3hr.
so 1hr 18min is 1.3 hrs
there are 60 seconds in 1 minute and 60 minutes in 1 hr, thus 60*60 seconds in 1hr, or 3600 seconds, so, 27 seconds is just 27/3600 hrs, or 0.0075 hrs.
so, 1.3 hr or 1.3000 hr for that matter plus 0.0075, is just
1.3075 hrs.
a)
so, they covered 26.2 miles in 1.3075 hrs, so the average speed is just 26.2/1.3075, or about 20.0382409177 miles/hr
b)