SOLUTION: Can you please help me solve this problem? A car dealer thinks it is easier to change spark plugs in Japanese cars than in American cars. They changed a number of spark plugs

Question 192056: Can you please help me solve this problem?
A car dealer thinks it is easier to change spark plugs in Japanese cars than in American cars. They changed a number of spark plugs in each kind of car and the results are given, in minutes below:
Japabese: 15,21,22,13,18,21,20,21
American: 19,24,19,16,19,23
At the 0.05 level of significance, is there sufficient evidence to back his theory?

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A car dealer thinks it is easier to change spark plugs in Japanese cars than in American cars. They changed a number of spark plugs in each kind of car and the results are given, in minutes below:
Japabese: 15,21,22,13,18,21,20,21
Sample mean = 18.875 ; s = 3.27054
------------------------------------------
American: 19,24,19,16,19,23
Sample mean = 20 ; s = 2.96648
----------------------------------
At the 0.05 level of significance, is there sufficient evidence to back his theory?
---
Ho: u(Jap) - u(Amer) = 0
H1: u(Jap) - u(Amer) < 0 (Claim)
-----------
I ran a 2-Sample t test and got the following:
test statistic: t =-0.6719
p-value: 0.2575
-----------------
Since the p-value is greater than 5%, fail to reject Ho.
Replacing one is no faster than replacing the other.
==============================
Cheers,
Stan H.
RELATED QUESTIONS
Please help me solve this word problem: Garrett and Chris have a summer job washing... (answered by stanbon)

A car dealer will sell you a used car for $6,549 with $549 down and payments of $205.67... (answered by rfer)

I have no idea if this is the right topic, but oh well. Here is the problem I am doing or (answered by jim_thompson5910)

Hello! I need help on this one math problem. It seems complicated but I know that it is... (answered by AnlytcPhil)

Please help me solve this problem. If it takes a car wash 2 hours and 10 minutes to... (answered by stanbon)

Sherman is repairing his car. He has removed the six spark plugs. four are good and two... (answered by stanbon)

Hai sir, Karen thinks of a number, multiplies it by 3 and then adds 10. Her answer is... (answered by Alan3354)

can you help me solve and graph {{{1/2x - 2/3y=-6}}} so far i tried y intercept=C/B and i (answered by checkley71)

Hi, Can you please help me solve for this, Doane−Seward: Applied Statistics in... (answered by stanbon)