Question

Answer the Question please Typed - Written or Excel Pictures But not as hand writing pictures

They need Z Values - Z Table

4. Suppose the speed limits in 13 countries in miles per hour are as follows: Country Highway Miles per Hour Italy 87 France 81 Hungary 75 Belgium 75 Portugal 75 Great Britain Spain Denmark Netherlands Greece Japan Norway 56 Turkey 56

This is A Z-Values - Z-Table Example

Answer 1

The first step is to find the mean speed limit.

Mean speed limit = 87 +81 + 75 + 75+75 + 70 +62 +62 +62 +62 +62 + 56+ 56 13

Mean speed limit = 68.08 miles per hours.

Variance = (87 - 68.08)2 +(81 – 68.08)2+(75-68.08)2 +(75-68.08)2 +(75 - 68.08)2+(70-68.08)2 +(62 - 68.08)2+(62 - 68.08)2+(62 - 68.08)2+(62 - 68.08)2 +(62-68.08)2 +(56-68.08) +(56-68.08) 13

Variance = 88.3787

Standard deviation =

ariance

Standard deviation =

V88.3787

Standard deviation = 9.4

Using the Z table below, the Z score for 98% confidence level equals 2.33 because 0.50 times of 0.98 = 0.49 and the value closest to 0.49 is 0.490.

The confidence interval equals =  $\bar{X}$$\pm$ Z $\sigma _{X}$

Confidence interval for the speed limit = 68.08 $\pm$ 2.33 $\times$ 9.4

Confidence interval for the speed limit = ( 46.18 , 89.98 )

Thus we can say with 98% confidence level that the expected value of the speed limit is between 46.18 and 89.98.