10+1/3y =1 what is the answer

1. 130°

I don't remember too many specifics from my past math classes, but I always remembered this because that is an upside-down mirror of the 130° angle.

2. 50°

A straight line is 180°, and 180 - 130 = 50.

7 0

3 years ago

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Bob Nale is the owner of Nale’s Quick Fill. Bob would like to estimate the mean number of gallons of gasoline sold to his custom

ira [324]

Answer:

a) The best estimator for the population mean is given by the sample mean $\hat \mu = \bar X = 5.70$

b) The 99% confidence interval would be given by (4.969;6.431)

c) We are 99% confident that the true mean for th number of gallons of gasoline sold to his customers is between 4.969 and 6.431.

Step-by-step explanation:

1) 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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=1.9$ represent the population standard deviation

n=45 represent the sample size

2) Part a

The best estimator for the population mean is given by the sample mean $\hat \mu = \bar X = 5.70$

3) Part b. Develop a 99 percent confidence interval for the population mean.

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$5.7-2.58\frac{1.9}{\sqrt{45}}=4.969$

$5.7+2.58\frac{1.9}{\sqrt{45}}=6.431$

So on this case the 99% confidence interval would be given by (4.969;6.431)

4) Part c. Interpret the meaning of part (b).

On this case we can say this: We are 99% confident that the true mean for th number of gallons of gasoline sold to his customers is between 4.969 and 6.431.

4 0

4 years ago