Plz help ASAP

At a local university, a sample of 49 evening students was selected in order to determine whether the average age of the evening

pav-90 [236]

Answer:

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

$p_v =2*P(z>4)=0.0000633$

When we compare the significance level $\alpha=0.1$ we see that $p_v$ so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.

Step-by-step explanation:

Data given and notation

$\bar X=23$ represent the sample mean

$\sigma=3.5$ represent the population standard deviation

$n=49$ sample size

$\mu_o =21$ 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 the average age of the evening students is significantly different from 21, the system of hypothesis would be:

Null hypothesis: $\mu = 21$

Alternative hypothesis: $\mu \neq 21$

The statistic is given by:

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

Calculate the statistic

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

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

P-value

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

$p_v =2*P(z>4)=0.0000633$

Conclusion

When we compare the significance level $\alpha=0.1$ we see that $p_v$ so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.

8 0

3 years ago

Can someone help me with this one please

Ket [755]

Answer:

mnxjzhsyushnauhJnnzuz

7 0

2 years ago

Two people are driving to work at different constant speeds. The graph below shows the distance traveled over time by driver 1.

Luden [163]

Answer:

5 mph

Step-by-sep explanation:

To find of out the difference between the speed of the two drivers in miles per hour (not in miles per minute), first, calculate the unit rate or speed of driver 1 using the graph, and driver 2 using the table given.

Unit rate/speed = distance travelled/time = y/x.

Speed of Driver 1/unit rate:

The graph shows 1.5 miles (y) is travelled in 2 minutes (x).

Convert the 2 minutes to hour, you will have:

$\frac{2}{60} = \frac{1}{30} hr$

Speed in mph = $\frac{y}{x} = \frac{1.5}{\frac{1}{30}} = 1.5*\frac{30}{1} = 45$

Speed of Driver 1 in mph = 45 mph

Speed of Driver 2/unit rate:

The table shows 2.5 miles (y) is travelled in 3 minutes (x).

Convert the 3 minutes to hour, you will have:

$\frac{3}{60} = \frac{1}{20} hr$

Speed in mph = $\frac{y}{x} = \frac{2.5}{\frac{1}{20}} = 2.5*\frac{20}{1} = 50$

Speed of Driver 2 in mph = 50 mph

Difference between the speed of the two drivers = 50 - 45 = 5 mph

4 0

3 years ago

Find the degree of this polynomial. 19x^9-2x^6+9x^5

Kamila [148]

Answer:

Step-by-step explanation:

The degree of a polynomial is the variable (in this case 1 variable) raised to the highest power.

Look at the first term: 19x^9

The variable is x

The highest power is 9

So the answer is 9.

4 0

2 years ago

How do you find the vertex & how do you know if a graph opens up or down help please asap

alex41 [277]

Standard form of a quadratic f(x) = ax^2 + bx + c
In a quadratic function you find the vertex using the formula x = -b/2a; once you find the x value, substitute it into the equation and solve for y.
To know if a parabola opens up or down you look at the coefficient of the x^2 term. If it is positive, the graph opens up; if it is negative, the graph opens down.

8 0

3 years ago