Answer:
And we can find this probability with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
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 hous spent studying the week before final exams 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 with this difference:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
Answer:
Step-by-step explanation:
given that a batch of 140 semiconductor chips is inspected by choosing a sample of 5 chips without replacement.
10 chips do not conform to customer requirements.
i.e. out of 140 chips 10 are defective and 130 are good
a) 5 chips can be selected form 140 chips in 140C5 ways
= 416965528
b) For containing exactly one non conforming chip we have one selected from 10 and other 4 selected from 130
No of ways = 
c) For atleast one nonconforming chip we can calculate as total - no non conforming
i.e. 
In general, the dependent variable will be by itself on the left side of the equation. Its value depends upon that of the independent variable embedded in some expression on the right side.
Answer:
Step-by-step explanation:
Total distance = 3 + 2.5 = 5.5mi/h
Total time = 0.75h + 2hr = 2. 75 hr
Average speed = 5.5 / 2.75 = 2