A 90% confidence interval for the mean speed driven by cars on East Main St. is (21, 45). What was the sample mean of this study? O 12 O 24 O 21 O 33A sample of 20 cupcakes found the interval for calories to be (150, 350). Which is the correct interpretation of the 95% condence interval? 0 none of the other sentences are correct 0 We are 95% condent that a sample of 20 cupcakes will nd 250 calories per cupcake. Q We are 95% condent that the true mean calorie content can be found with a sample of 150 to 350 cupcakes. 0 We are 95% condent that the true mean calorie content in cupcakes is between 150 and 350 calories. What is the t value associated with 90% confidence and a sample size of 18? Approximately. You may use the t distribution table. You can also ask Stata: ttail.pdf + O 1.73 O 1.14 O 2.85 O 0.91