Answer:
Step-by-step explanation:
<em>Find the equation of the dashed line</em>
The line pass through the points
-----> is the y-intercept of the line
Find the slope of the line m
The formula to calculate the slope between two points is equal to
substitute the values
Remember that
The equation of the line into slope intercept form is equal to
we have
substitute
<em>Find the inequality</em>
we know that
The solution of the inequality is the shaded area below the dashed line
so
Answer:
There is a probability of P=0.94 that at least 81 rolls are needed to get the sum of 307.
Step-by-step explanation:
The roll of a six-sided die sum has this parameters:
Mean: 3.5
Standard deviation: 1.7
If the die is rolled 81 times, the distribution of the sum of the 81 rolls will have the following parameters:
Note: the variance of the sum of random variables is equal to the sum of the variance of the individual variables.
Then, we can calculate the probabilties that the sum of 81 rolls is lower than 307.
There is 94% of chances that the sum of 81 rolls is lower than 307, so there is a probability of P=0.94 that at least 81 rolls are needed to get the sum of 307.