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A man who moves to a new city sees that there are two routes he could take to work. A neighbor who has lived there a long time tells him Route A will average 5 minutes faster than Route B. The man decides to experiment. Each day he flips a coin to determine which way to go, driving each route 10 days. He finds that Route A takes an average of 48
?minutes, with standard deviation 44 minutes?,
and Route B takes an average of 49 minutes, with standard deviation 1 minute.
Histograms of travel times for the routes are roughly symmetric and show no outliers. Complete parts a and b. Use alpha?equals=0.05

Respuesta :

shejladautovic

Answer:

0.3 to 2.3 min

Step-by-step explanation:

n1=n2=10

x1=48

x2=49

s1=4

s2=1

Determine the deegres of freedom.

[tex]\delta=\frac{(\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2})^2}{\frac{(\frac{s_1^2}{n1})^2}{n_1-1}+\frac{(\frac{s_1^2}{n1})^2}{n_2-1}}=10.14[/tex]

t=2.037 (student's appendix)

[tex]E=t\sgrt(\frac{s_1^2}{n_1}+\frac{s^2_2}{n_2})=1.3[/tex]

[tex] (x_1-x_2)-E=(48-49)-1.3=-2.3[/tex]

[tex] (x_1-x_2)+E=(48-49)+1.3=0.3[/tex]

We are 95% confident that average commuting time for  rute A is between 0.3 and 2.3 min shorter than for rute B.

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