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Toby wants to know the average price of new cars at a particular dealearship. He randomly selects a sample of 35 cars and finds that the average price to be $20900$20900 with a standard deviation of $1400$1400. What is the 90% confidence interval for the mean price of cars at this particular dealership?
a.) Which distribution table will be used to find the critical value and why?
A.) t-table because the population standard deviation is unknown
B.) Z-table because the population standard deviation is unknown
C.) Z-table because the population standard deviation is known
D.) t-table because the population standard deviation is known
b.) With 90% confidence, we can say the true population mean price of cars at this dealership is between $ and $ .
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