Help me pls answers are rounded to 4 decimal places

6. The random variable X has a normal distribution with mean 5.2 and variance 9. Find the value of x, call it x0, such that P(x 5 x0) = 0.8770 7. The random variable X has a normal distribution with mean 5 and standard deviation 2.3. Find the value of 3:, call it x0, such that P(x,, 5 x S 7) = 0.6858 8. A sample of size 78 produced the sample mean of 16.4. Assuming the population standard deviation 3.3, compute a 99% confidence interval for the population mean u. 9. The operations manager of a large production plant would like to measure the amount of time (in minutes} a worker takes to assemble a new electronic component. The observed data by the manager are 5.21, 4.31, 3.64, 4.17, 3.88, 4.52, 3.81, 4.71, 8.92. Note: Round your answers to 4 decimal places a. Estimate the population mean and standard deviation b. Construct a 98% Confidence interval