ANSWER THESE ILL GIVE U BRAINLIEST

Marcella had $15. She bought some books. After that she had $6 left.

KengaRu [80]

Answer:

B.) 15 - A = 6

Step-by-step explanation:

The equation shows that Marcella had $15 then bought something (A), and now she has 6 dollars left.

15 - A = 6

8 0

4 years ago

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An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 100100 engin

Margaret [11]

Answer:

Null hypothesis: $\mu \geq 7.3$

Alternative hypothesis: $\mu < 7.3$

$z=\frac{7.2-7.3}{\frac{0.81}{\sqrt{100}}}=-1.235$

$p_v =P(z$

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so then we can conclude that the mean pressure for the automobile engines is not significantly less than 7.3 at 1% of significance.

Step-by-step explanation:

1) Data given and notation

$\bar X=7.2$ represent the sample mean

$\sigma=0.81$ represent the population standard deviation

$n=100$ sample size

$\mu_o =7.3$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

2) State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean pressure is lower than the specificated value 7.3, the system of hypothesis are :

Null hypothesis: $\mu \geq 7.3$

Alternative hypothesis: $\mu < 7.3$

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

3) Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{7.2-7.3}{\frac{0.81}{\sqrt{100}}}=-1.235$

4) P-value

Since is a one-side lower test the p value would given by:

$p_v =P(z$

5) Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, so we can conclude that the mean pressure for the automobile engines is not significantly less than 7.3 at 1% of significance.

7 0

3 years ago

If $190 is invested at an interest rate of 11% per year and is compounded continuously, how much will the investment be worth in

dangina [55]

Answer:

$295.01

Step-by-step explanation:

Using the compounding continuously formula, we are looking for A. We have that P = 190; r = .11 (always use the decimal form of the rate!); and t = 4. Filling in we have:

$A=190e^{(.11)(4)}$

Simplifying that multiplication:

$A=190e^{.44}$ .

On your calculator, raise e to the .44 power to get

A = 190(1.552707219) and

A = $295.01

5 0

3 years ago

Tony can type at a constant rate of 110 words every 2 minutes.

kati45 [8]

Answer:

W = 55T

Step-by-step explanation:

He types 110 / 2 = 55 words every minute. Thus, W = 55T

8 0

3 years ago

Determine which of the following statements is true for the function<br> g(x) = 415 - 3x + 24- 1.

Zarrin [17]

Answer:

?

Step-by-step explanation:

what are the statements??

4 0

3 years ago