The graph below shows the number of spoons arranged on different numbers of tables in a room:
2 answers:
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Answer:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:And we can find this probability using the complement rule:
Answer: The answer is (b) The ranger will need to clear trail for more than 10 2/3 additional hours.
Step-by-step explanation: Given that a park ranger would like to clear more than 10 mi of trail. Till now, he has cleared 2 mi. From now on, he can clear 3/4 mi of trail each hour.
Since 2 mi of the trail has already been cleared, so the trail that is left to be cleared = 10 - 2 = 8 mi.
Let, the park ranger will work for 'x' more hours. So, we have
Thus, the park ranger will need to work for 10 2/3 more hours.
Hence, the correct option is (b) The ranger will need to clear trail for more than 10 2/3 additional hours.