Answer:
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
Step-by-step explanation:
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 = 21 - 1 = 20
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 20 degrees of freedom(y-axis) and a confidence level of . So we have T = 1.7247
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 311.9 - 19.42 = $292.48
The upper end of the interval is the sample mean added to M. So it is 311.9 + 19.42 = $331.32
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
From the given recurrence, it follows that
and so on down to the first term,
(Notice how the exponent on the 2 and the subscript of <em>a</em> in the first term add up to <em>n</em> + 1.)
Denote the remaining sum by <em>S</em> ; then
Multiply both sides by 2 :
Subtract 2<em>S</em> from <em>S</em> to get
So, we end up with
Answer:
D E F
Step-by-step explanation:
Have a good day :)
Total number of students in the class = 36
Number of students wearing blue shirts = (1/6) * 36
= 36/6
= 6
Number of students wearing white shirts = (2/3) * 36
= 2 * 12
= 24
Then
Number of students not wearing blue or white shirts in the class = 36 - (6 + 24)
= 36 - 30
= 6
So 6 students in the class are wearing a shirt other than a blue or a white shirt. I hope the procedure is clear enough for you to understand.
Answer:
69
Step-by-step explanation:
nice ;)