Mathematics, 16.03.2020 20:18 bobbycisar1205

Some research suggests that police officers are more likely to make an arrest in the presence of bystanders. If mentally disordered suspects attract more attention from bystanders, they may be more likely to be arrested than nonmentally disordered suspects. Assume that the average number of bystanders when police encounter a suspect is 3.58. In a sample of 20 police encounters with mentally disordered suspects, Engel and Silver (2001) found an average of 7.03 bystanders (standard deviation = 9.42).Perform a hypothesis test to determine if there are more bystanders when the suspect is mentally disordered. Use a 0.01 level of statistical significance. Which distribution, z or t, will you use?

Answers: 1

Show answers

Answers

Answer from: ddmorse2015owug6f

$t=\frac{7.03-3.58}{\frac{9.42}{\sqrt{20}}}=1.638$

$p_v =P(t_{(19)}1.638)=0.0589$

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 have enough evidence to FAIL to reject the null hypothesis, and we can conclude that the true mean is not significantly higher than 3.58 at 5% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=7.03$ represent the sample mean

s=9.42 represent the sample standard deviation

n=20 sample size

$\mu_o =3.58$ 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)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is higher than 3.58 :

Null hypothesis: $\mu \leq 3.58$

Alternative hypothesis: $\mu 3.58$

Since we don't know the population deviation, 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:

$t=\frac{7.03-3.58}{\frac{9.42}{\sqrt{20}}}=1.638$

P-value

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

df=n-1=20-1=19

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

$p_v =P(t_{(19)}1.638)=0.0589$

Conclusion

Answer from: Quest

4hours and 40 mins she would be 120 meters high

Answer from: Quest

you would need to also lose 1 point for each of the other outcomes for it to be fair.

step-by-step explanation:

Another question on Mathematics

Mathematics, 21.06.2019 19:30

Me. i can't figure out this question. give an explanation too. .

Answers: 1

Answer

Mathematics, 21.06.2019 20:20

Select the correct answer from each drop-down menu. the length of a rectangle is 5 inches more than its width. the area of the rectangle is 50 square inches. the quadratic equation that represents this situation is the length of the rectangle is inches.

Answers: 1

Answer

Mathematics, 21.06.2019 21:30

A(1,1) b(-3,0) c(-4,-1) d(3,-2) drag it to correct position

Answers: 2

Answer

Mathematics, 21.06.2019 22:10

2. using calculations based on a perpetual inventory system, determine the inventory balance altira would report in its august 31, 2021, balance sheet and the cost of goods sold it would report in its august 2021 income statement using the average cost method. (round "average cost per unit" to 2 decimal places.)

Answers: 1

Answer

You know the right answer?

Some research suggests that police officers are more likely to make an arrest in the presence of bys...

Questions