Answer:
28.5 psi and 32.1
Step-by-step explanation:
Since the question already provided the mean (30.3 psi) and the margin of error with confidence of 95% (+ or - 1.8 psi), simply add and subtract the margin of error to the mean value to find the confidence interval:
Lower bound:
L = 30.3 - 1.8 = 28.5
Upper bound:
H = 30.3 +1.8 = 32.1
Therefore, the mean tire pressure of tires on new Toyota cars is between 28.5 psi and 32.1 psi.