BluSeaa

08.02.2021 • 

Mathematics

Parents of teenage boys often complain that auto insurance costs more, on average, for teenage boys than for teenage girls. A group of concerned parents examines a random sample of insurance bills. The mean annual cost for 36 teenage boys was $678. For 23 teenage girls, it was $556. From past years, it is known that the population standard deviation for each group is $180. Determine whether or not you believe that the mean cost for auto insurance for teenage boys is greater than that for teenage girls. Conduct a hypothesis test at the 5% level. NOTE: If you are using a Student's t-distribution for the problem, including for paired data, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

Ответ:

billy12008

15.06.2022

Mathematics

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1)4x+2y=8
When y=0 (x-intercept) 
4x=8
x=8/4
x=2
When x=0 (y-intercept) 
2y=8
y=8/2
y=4

2) *Do same again*
-5x+3y=-15
-5x=-15
x=3
3y=-15
y=-5

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