Dana walks 3/4 mile in 1/4 hour. what is dana's walking rate in miles

An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 180180 engin

tiny-mole [99]

Answer:

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

$p_v =P(Z$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=4.6$ represent the sample mean

$\sigma=0.9$ represent the population standard deviation

$n=180$ sample size

$\mu_o =4.8$ represent the value that we want to test

$\alpha=0.1$ 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)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if thetrue mean is below the specifications, the system of hypothesis would be:

Null hypothesis: $\mu \geq 4.8$

Alternative hypothesis: $\mu < 4.8$

If we analyze the size for the sample is > 30 and we know the population deviation so 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".

Calculate the statistic

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

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

P-value

Since is a one sided test the p value would be:

$p_v =P(Z$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

4 0

3 years ago

Derek was 4 years 2 months old when he joined school. Today he is 11 years 1 month old. For how long has he been in school?

lora16 [44]

Answer:

hi

Step-by-step explanation:

first of all,we should do this:

1 year is 12 month

amd 4 year is 48 month(12×4)

then we must add 2 months (wich is given) to 48

He was 50 months old when he started school

and we should find how old is he now

11 ×12=132months

132+1=133months

133-50=83 ( he has been 83 months in school)

let's turn it to years 6 years 11 months

( for finding years you should divide 83 to 12)

hope it helps

6 0

2 years ago

Prove that the product of any two consecutive natural numbers is even.

Vitek1552 [10]

Answer with Step-by-step explanation:

Let us assume the 2 consecutive natural numbers are 'n' and 'n+1'

Thus the product of the 2 numbers is given by

$Product=n(n+1)\\\\$

We know that the sum of 'n' consecutive natural numbers starting from 1 is

$S_n=\frac{n(n+1)}{2}\\\\\therefore n(n+1)=2\times S_n............(i)$

Thus from equation 'i' we can write

$Product=2\times S_n$

As we know that any number multiplied by 2 is even thus we conclude that the product of 2 consecutive numbers is even.

6 0

3 years ago

How to model 4÷2/3??

stealth61 [152]

Answer:

We have 4 x ( 3 / 2 ) = 12 / 2 = 6;

Step-by-step explanation:

4 0

3 years ago

Which expression is equivalent to -1/4 x + 1/2?

Anna71 [15]

The expression is given by:

$-\frac{1}{4}x+ \frac{1}{2}$

So we need to find an equivalent equation for this problem. Then, we will apply some mathematical rules:

Extracting the common factor 1/4, then:

$\frac{1}{4}(-x+2})$

Or extracting the common factor -1/4, then:

$-\frac{1}{4}(x-2})$

So, comparing these solutions with the answers about, there is no any answer that matches.

7 0

3 years ago

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