A biased dice is thrown.
1 answer:
Given:
A biased dice is thrown 300 times.
Table of probabilities of each score.
To find:
The expected number of times the score will be odd.
Solution:
Odd numbers on the dice are 1, 3, 5. The sum of their probability is
Even numbers on the dice are 2, 4, 6. The sum of their probability is
Now, the expected number of times the score will be odd is
Therefore, the expected number of times the score will be odd is 210.
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Answer:
Right triangle
Step-by-step explanation:
Using pythagorean theorem,
Hence satisfied. So it is right triangle.
Answer:
Y will arrive earlier than X one fourth of times.
Step-by-step explanation:
To solve this, we might notice that given that both events are independent of each other, the joint probability density function is the product of X and Y's probability density functions. For an uniformly distributed density function, we have that:
Where L stands for the length of the interval over which the variable is distributed.
Now, as X is distributed over a 1 hour interval, and Y is distributed over a 0.5 hour interval, we have:
.
Now, the probability of an event is equal to the integral of the density probability function:
Where A is the in which the event happens, in this case, the region in which Y<X (Y arrives before X)
It's useful to draw a diagram here, I have attached one in which you can see the integration region.
You can see there a box, that represents all possible outcomes for Y and X. There's a diagonal coming from the box's upper right corner, that diagonal represents the cases in which both X and Y arrive at the same time, under that line we have that Y arrives before X, that is our integration region.
Let's set up the integration:
We have used here both the independence of the events and the uniformity of distributions, we take the 2 out because it's just a constant and now we just need to integrate. But the function we are integrating is just a 1! So we can take the integral as just the area of the integration region. From the diagram we can see that the region is a triangle of height 0.5 and base 0.5. thus the integral becomes:
That means that one in four times Y will arrive earlier than X. This result can also be seen clearly on the diagram, where we can see that the triangle is a fourth of the rectangle.
