What are the zeros of the function below? Check all that apply

A random sample of n = 40 observations from a quantitative population produced a mean x = 2.2 and a standard deviation s = 0.29.

zmey [24]

Answer:

$t=\frac{2.2-2.1}{\frac{0.29}{\sqrt{40}}}=2.18$

$df=n-1=40-1=39$

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

$p_v =P(t_{(39)}>2.18)=0.0177$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and then the population mes seems to be higher than 2.1 at 5% of significance

Step-by-step explanation:

Data given and notation

$\bar X=2.2$ represent the sample mean

$s=0.29$ represent the sample standard deviation

$n=40$ sample size

$\mu_o =2.1$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t 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 the mean is higher than 2,1, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2.1$

Alternative hypothesis: $\mu > 2.1$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-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:

$t=\frac{2.2-2.1}{\frac{0.29}{\sqrt{40}}}=2.18$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=40-1=39$

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

$p_v =P(t_{(39)}>2.18)=0.0177$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and then the population mes seems to be higher than 2.1 at 5% of significance

7 0

3 years ago

I need help!! on 9 and 10 plzz help

Alexxandr [17]

9. 1/3+(x+20)+(x-10)+40=360 10. 1/2x+1/2x+(x-15)+(x-25)+100=540

1/3+2x+50=360 4x+60=540

(3/1) 1/3+2x=300(3/1) 4x/4=480/4

2x=300 X=120

————

2

W=150

6 0

3 years ago

On a certain hot summer's day, 391 people used the public swimming pool. The daily prices are $1.25 for children and $2.25 for

Tomtit [17]

127 children and 264 adults swam at the public pool that day

Step-by-step explanation:

On a certain hot summer's day

391 people used the public swimming pool
The daily prices are $1.25 for children and $2.25 for adults
The receipts for admission totaled $752.75

We need to find how many children and how many adults swam at the public pool that day

Assume that the number of children is x and the number of adult is y in that day

∵ x children swam that day

∵ y adults swam that day

∵ 391 people used the swimming pool that day

- Add x and y, then equate the sum by 391

∴ x + y = 391 ⇒ (1)

∵ The daily price for children is $1.25 per child

∵ The daily price for an adult is $2.25

∵ The receipts for admission totaled $752.75

- Multiply x by 1.25 and y by 2.25, then add the products and

equate the sum by 752.75

∴ 1.25x + 2.25y = 752.75

- Divide each term by 1.25 to simplify the equation

∴ x + 1.8y = 602.2 ⇒ (2)

Now we have a system of equations to solve it

Subtract equation (1) from equation (2) to eliminate x

∵ (x - x) + (1.8y - y) = 602.2 - 391

∴ 0.8y = 211.2

- Divide both sides by 0.8

∴ y = 264

- Substitute the value of y in equation (1) to find x

∵ x + 264 = 391

- Subtract 264 from both sides

∴ x = 127

127 children and 264 adults swam at the public pool that day

Learn more:

You can learn more about the system of equations in brainly.com/question/2115716

#LearnwithBrainly

6 0

3 years ago

4x - 2 + y = 6 - 2x for x

Vlada [557]

Answer:

4x

Step-by-step explanation:

8 0

3 years ago

Frankie paid $11.75 for the movie tickets and $4.75 for popcorn and drink. How much did Frankie spend?

olasank [31]

Answer:

he spent $16.5

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers