Answer:
Step-by-step explanation:
For each component, there are only two possible outcomes. Either it fails, or it does not. The components are independent. We want to know how many outcomes until r failures. The expected value is given by
In which r is the number of failures we want and p is the probability of a failure.
In this problem, we have that:
r = 1 because we want the first failed unit.
The expected number of systems inspected until the first failed unit is 2.5
Answer:
Step-by-step explanation:
The standard deviation is the square root of the variance, and the variance is found by using the mean. So we will do that first. I will use the population variance as opposed to the sample variance since our set of numbers is small.
The mean: 8 + 12 + 15 + 17 + 18 = 70 and divide that by 5 to get
and use this to find the variance in the formula:
it is a bit difficult to enter that formula in correctly, but here's how it works mathematically:
Squaring this ensures us that we don't end up with zero, which would be useless.
so
which means that the standard deviation is
s = 3.633
(If you do it with n-1 = 4 in the denominator of the variance, you get a standard deviation of 4.062)
Answer:
The fraction of one pound of cheese to be used in each sandwich is 1/8
Step-by-step explanation:
Here, we have a question that requires the method of dealing with the division of fractions.
To divide a fraction by a whole number, we multiply the denominator of the fraction by the whole number as follows;
Quantity of cheese Shane has = 1/2 pound
Number of sandwiches to be made = 4
Amount of cheese per sandwich = 1/2÷4 = 1/8.