Suppose lengths of text messages are normally distributed and have a known population standard deviation of 3 characters and an unknown population mean. A random sample of 22 text messages is taken and gives a sample mean of 31 characters. What is the correct interpretation of the 90% confidence interval? Select the correct answer below: We estimate that 90% of text messages have between 29.95 and 32.05 characters. We estimate with 90% confidence that the true population mean is between 29.95 and 32.05 characters. We estimate with 90% confidence that the sample mean is between 29.95 and 32.05 characters.