Use the t-Distribution to answer the following questions: (Round your critical values to three decimal places.) 1. Find the critical value, tı –, n-1, associated with a 98% confidence interval if there are 16 degrees of freedom. What is theCritical Value (three decimals)?

2. Find the negative critical value, t q ,n–1, associated with an 80% confidence interval if there are 28 degrees of freedom. What is the Critical Value (three decimals)?

3. Find the critical value, t1-9, n-1, associated with a 95% confidence interval with 7 degrees of freedom. What is the Critical Value (three decimals)?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?