PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!! I CANNOT RETAKE THIS AND I NEED ALL CORRECT ANSWERS ONLY!!!

For the population, scores on the test are normally distributed with μ = 70 and σ = 15. The sample of n = 25 students had a mean

AysviL [449]

Answer:

$z=\frac{75-70}{\frac{15}{\sqrt{25}}}=1.67$

$p_v =2*P(t_{24}>1.67)=0.108$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis, and the the actual mean is not significant different from 70.

Explanation:

1) Data given and notation

$\bar X=75$ represent the sample mean

$\sigma=15$ represent the standard deviation for the population

$n=25$ sample size

$\mu_o =70$ 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 determine if the mean is different from 70, the system of hypothesis would be:

Null hypothesis: $\mu = 70$

Alternative hypothesis: $\mu \neq 70$

We know the population deviation, so for this case 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:

$z=\frac{75-70}{\frac{15}{\sqrt{25}}}=1.67$

Calculate the P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=25-1=24$

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

$p_v =2*P(t_{24}>1.67)=0.108$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis, and the the actual mean is not significant different from 70.

3 0

4 years ago

What is the strength of electric field EpEp 0.60 mmmm from a proton? Express your answer to two significant figures and include

disa [49]

Answer:

3.99*10^-3N/C

Explanation:

Using

Ep= kq/r²

Where r = 0.6mm = 0.6*10^-3m

K= 8.9*10^9 and q= 1.6*10^-19

So = 8.9*10^9 * 1.6*10^-19/0.6*10^-3)²

= 3.99*10^-3N/C

8 0

3 years ago

You extend an impromptu invitation to a friend for dinner. The only food you have is a couple of frozen steaks. You wish to defr

kakasveta [241]

Answer:

Microwave: Radiation

Water: Conduction, convection & radiation.

Explanation:

When we heat a food using microwave then the water content of the food is only heated by the microwave.

Microwaves make the molecules of water vibrate frequently with a frequency closer to the frequency of microwaves and this increases the kinetic energy of the molecules which produces heat in the water molecules this heat then propagates to the whole food by conduction and convection, but the heat enters the food only via radiation.

Now when the food item is kept into warm water then the molecules closer to the food heat the food by conduction through direct energy transfer by lattice vibrations and when they become cooler than the mass of water all around then due to density difference they settle down and their place is occupied by warmer molecules around in the fluid leading to convection.

Radiation of energy from a mass occurs continuously irrespective of the medium present there. So the heat of water also enters the food by radiation of energy from the water molecules.

3 0

3 years ago

What is concave mirror

Licemer1 [7]

Answer:

A curved mirror is a mirror with a curved reflecting surface. The surface may be either convex or concave. Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices.

Explanation:

8 0

4 years ago

The type of circuit in which there is only one path for an electric current to flow is known as a _____ circuit. Question 6 opti

-BARSIC- [3]

Answer:

series circuit

Explanation:

A series circuit is wired with only one path for the current to flow through all the devices in a row and back to the starting point.

6 0

3 years ago