Records of 40 used passanger cars and 40 used pickup tricks were randomly selected to investigate whether there was any difference in the mean time in years that they were kept by original owner before being sold. for cars, the mean was 5.3 years with standard deviation 2.2 years. for pickup trucks, the mean was 7.1 years with standard deviation 3.0 years. test the hypothesis that there is a difference in the means against the null hypothesis that there is no difference. use the 1% level of significance.

There is significant difference between the two average times

Step-by-step explanation:

This test would be comparison of two means where only sample variances and means are given.

Since variances are unequal we have to do t test for unequal variances.

(Two tailed test)(x represents grou I cars, and Y group 2 trucks)

Group   Group One     Group Two  

Mean5.3007.100

SD2.2003.000

SEM0.3480.474

N40      40  

The mean of Group One minus Group Two equals -1.800

standard error of difference = 0.588

t = 3.0601

 df = 78

The two-tailed P value equals 0.0030

Since p <1% we reject null hypothesis

There is significant difference between the two average times

im sorry but no. i just need to answer for 50 poonts oof

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: