Previously, an organization reported that teenagers spent 4.5 hours per week, on average, on the phone. the organization thinks that, currently, the mean is higher. fifteen randomly chosen teenagers were asked how many hours per week they spend on the phone. the sample mean was 4.75 hours with a sample standard deviation of 2.0. conduct a hypothesis test. the null and alternative hypotheses are:

The teenagers spent 4.5 hours per week, on average, on the phone.

Step-by-step explanation:

We are given the following in the question:  

Population mean, μ = 4.5

Sample mean, = 4.75

Sample size, n = 15

Alpha, α = 0.05

Sample standard deviation, s = 2

First, we design the null and the alternate hypothesis

We use one-tailed(right) t test to perform this hypothesis.

Formula:

Putting all the values, we have

Now,

Since,                  

We accept the null hypothesis.  Thus, the teenagers spent 4.5 hours per week, on average, on the phone. The sample contradicted the organization's claim.

There is no evidence that the population mean is greater than hours.

Step-by-step explanation:

Given:

Step 1 :

Null hypothesis:

Alternative hypothesis:  

Since the alternative hypothesis has a greater than symbol, it is a right-tailed hypothesis test.

Significance level is

Step 2:

The Test statistic of the organization

The p-value for a right-tailed test is given by:  

Step 3:

Now,

at level of significance, degree of freedom

Since,

so, accept the null hypothesis. Thus, the teenagers spent hours per week, on average, on the phone. The sample contradicted the organization's claim.

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answer:   segregation violated the equal protection clause of the 14th amendment, which holds that no state can “deny to any person within its jurisdiction the equal protection of the laws.”

details/explanation:

brown v. board of education of topeka, decided by the us supreme court in 1954, ruled that all americans are entitled to the same civil liberties and protections in regard to access to education. until that decision, it was legal to segregate schools according to race, so that black students could not attend the same schools as white students.   an older supreme court decision, plessy v. ferguson (1896), had said that separate, segregated public facilities were acceptable as long as the facilities offered were equal in quality.   in the case of brown v. board of education, that standard was challenged and defeated.   segregation was shown to create inequality, and the supreme court unanimously ruled segregation to be unconstitutional.

the ruling was important in advancing civil rights because it affirmed that the 14th amendment applies to all rights and privileges of citizens, including access to   education.   this was being violated by states whose laws supported the segregation of schools.   section 1 of the 14th amendment reads as follows:

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step-by-step explanation: