Answer:
24.2(to the nearest tenth)
Step-by-step explanation:
The question is ungrouped data type
standard deviation =√ [∑ (x-μ)² / n]
mean (μ)=∑x/n
=
=33.3
x-μ for data 5, 5, 6, 12, 13, 26, 37, 49, 51, 56, 56, 84 will be
-28.3, -28.3, -27.3, -21.3, -7.3, 3.7, 15.7,17.7, 22.7,22.7,50.7
(x-μ)² will be 800.89, 800.89,745.29,453.69,53.29,13.69,246.49,313.29,515.29,515.29,2570.49
∑ (x-μ)² will be = 7028.59
standard deviation = √(7028.59 / 12)
=24.2
Answer:
The 99% confidence interval for the mean diameter of pieces from this machine is between 0.93 and 1.07.
Step-by-step explanation:
Sample mean:
Sum of all values divided by the number of values. So
Sample standard deviation:
Square root of the sum of the differences between each value and the mean, divided by the 1 less than the sample size. So
Confidence interval:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 9 - 1 = 8
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of . So we have T = 3.355
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 1 - 0.07 = 0.93
The upper end of the interval is the sample mean added to M. So it is 1 + 0.07 = 1.07
The 99% confidence interval for the mean diameter of pieces from this machine is between 0.93 and 1.07.
Answer:
a) 20 ways
b) 10 ways
Step-by-step explanation:
When the order of selection/choice matters, we use Permutations to find the number of ways and if the order of selection/choice does not matter, we use Combinations to find the number of ways.
Part a)
We have to chose 2 objects from a group of 5 objects and order of choice matters. This is a problem of permutations, so we have to find 5P2
General formula of permutations of n objects taken r at time is:
Using the value of n=5 and r=2, we get:
Therefore, we can choose 2 objects from a group of 5 given objects if the order of choice matters.
Part b)
Order of choice does not matter in this case, so we will use combinations to find the number of ways of choosing 2 objects from a group of 5 objects which is represented by 5C2.
The general formula of combinations of n objects taken r at a time is:
Using the value of n=5 and r=2, we get:
Therefore, we can choose 2 objects from a group of 5 given objects if the order of choice does not matters.