Answer
given,
work = 5 J
spring stretch form 30 cm to 39 cm
x = 0.39 - 0.30 = 0.09 m
k = 1234.568 N/m
a) work when spring is stretched from 32 cm to 34 cm
x₂= 0.34 -0.30 = 0.04 m
x₁ = 0.32 - 0.30 = 0.02
W = 0.741 J
b) F = k x
25 = 1234.568 × x
x = 0.0205 m
x = 2.05 cm
Answer:
And we can find this probability using the complement rule and the normal standard table or excel:
The firgure attached illustrate the problem
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 retirement savings 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 and the normal standard table or excel:
The firgure attached illustrate the problem
