why might you want to use the commutative property to change the order of the intergers in the following sum before adding? -80+

Help:( i’ll give brainliest

almond37 [142]

My gut says go with 5/7

7 0

3 years ago

Charlie made $198 for 11 hours of work. At the same rate, how many hours would he have to work to make $126?

goldenfox [79]

Answer:

Charlie would have to work 7 hours to make $126.

Step-by-step explanation:

198 ÷ 11 = 18

$18 - 1 hour

126 ÷ 18 = 7

4 0

3 years ago

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

3 years ago

E) 3 - 2x = 15 <br>what is x

Anestetic [448]

3 - 2x = 15

-2x = 15 - 3

-2x = 12

x = 12 ÷ 2

x = 6

3 0

3 years ago

Read 2 more answers

A one-tailed test is a a. hypothesis test in which rejection region is in one tail of the sampling distribution b. hypothesis te

garri49 [273]

Answer:

Option A) One tailed test is a hypothesis test in which rejection region is in one tail of the sampling distribution

Step-by-step explanation:

One Tailed Test:

A one tailed test is a test that have hypothesis of the form

$H_0: \bar{x} = \mu\\H_A: \bar{x} < \mu\text{ or } \bar{x} > \mu$

A one-tailed test is a hypothesis test that help us to test whether the sample mean would be higher or lower than the population mean.
Rejection region is the area for which the null hypothesis is rejected.
If we perform right tailed hypothesis that is the upper tail hypothesis then the rejection region lies in the right tail after the critical value.

If we perform left tailed hypothesis that is the lower tail hypothesis then the rejection region lies in the left tail after the critical value.

Thus, for one tailed test,

Option A) One tailed test is a hypothesis test in which rejection region is in one tail of the sampling distribution

6 0

3 years ago