Answer:
1)
For this case we can interpret that the expected variation around the mean is about 3.3 people approximated
2)
And we can use the normal approximation given by:
And we can use the z score formula given by:
And if we find the z score for 16 we got:
And we can find this probability using the normal standard distribution or excel and we got:
3) For this case we can conclude that the probability to find 16 or more individuals left handed in a sample of 120 is about 0.112 or 11.2%
Step-by-step explanation:
Let X represent the random variable for the number of residents who are left handed
And for this case we can model this variable with this distirbution:
Part 1
The mean is given by:
And the deviation would be:
For this case we can interpret that the expected variation around the mean is about 3.3 people approximated
Part 2
We want to calculate this probability:
And we can use the normal approximation given by:
And we can use the z score formula given by:
And if we find the z score for 16 we got:
And we can find this probability using the normal standard distribution or excel and we got:
Part 3
For this case we can conclude that the probability to find 16 or more individuals left handed in a sample of 120 is about 0.112 or 11.2%