The 95% confidence interval (CI) for sodium content level in 50 nursing home patients is (4,250 mg/day, 4,750 mg/day). What does this CI tell us?
a) The true sodium content is between 4,250 mg/day and 4,750 mg/day with 95% confidence.
b) The true sodium content is exactly 4,500 mg/day.
c) The true sodium content is outside the given interval.
d) The sodium content level cannot be determined with confidence from the interval.