Answer:
And the best option would be:
C. [17.42,20.78]
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
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".
represent the sample mean
population mean (variable of interest)
s=1.5 represent the sample standard deviation
n=9 represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
In order to calculate the critical value
we need to find first the degrees of freedom, given by:
Since the Confidence is 0.99 or 99%, the value of
and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,8)".And we see that
Now we have everything in order to replace into formula (1):
And the best option would be:
C. [17.42,20.78]
Answer:
The population parameter of this study is the population mean.
Step-by-step explanation:
A population parameter is a numerical measure representing a certain characteristic of the population. For example, population mean, population variance, population proportion, and so on.
The population parameter is computed using all the values of the population.
The population parameter can be estimated using the sample statistic. If the value of the population parameter is not known, then a random sample of large size, say <em>n</em> ≥ 30 can be selected from the population and the statistic value can be computed. This statistic value is considered as the point estimate of the parameter. It is also known as the unbiased estimator of the parameter.
In this case the survey involved sampling of 1500 Americans to estimate the mean dollar amount that Americans spent on health care in the past year.
The sample selected is used to compute the sample mean dollar amount that Americans spent on health care.
So, the population parameter of this study is the population mean.
it would be C i think hope this helps
1. 8c^2-26c+15= (4c-3) (2c-5). Break the expression into groups: =(8c^2-6c)+(-20c+15). Factor out 8c^2-6c: 2c(4c-3). Factor out -5 from -20c+ 15: -5(4c-3). Lastly factor out common term (4c-3) and thats how you'll get your answer (4c-3) (2c-5).
2. common factors for 270 and 360 is 90.To find this write the factors of each and find the largest one.270: 1, 270, 2, 135, 3, 90, 5, 54, 6, 45, 9, 30, 10, 27, 15, 18360: 1, 360, 2, 180, 3, 120, 4, 90, 5, 72, 6, 60, 8, 45, 9, 40, 10, 36, 12, 30, 15, 24, 18, 20
3. The factors for 8 a3b2 and 12 ab4 is 4. because 8: 1, 2, 4, 812: 1, 2, 3, 4, 6, 12.
4. 81a^2+36a+4= (9a+2)^2. Break down the expression into groups: (81a^2+18a)+(18a+4). Factor out 9a from 81a^2 +18a: 9a(9a+2). Factor out 2 from 18a+4: 2(9a+2). so the groups you got are now 9a(9a+2)+2(9a+2). Lastley factor out common term (9a+2) to get (9a+2) (9a+2). Finally you get the answer (9a+2)^2.
5. mn-15+3m-5n= (n+3)(m-5). factor out m from nm+3m: m(n+3). Factor out -5 from -5n-15: -5(n+3). And thats how you get the number (n+3)(m-5)
Hope this helped :) Have a great day