Hello, I need help solving these problems. Please help me by solving it and provide explanations.

Problem 3. We destroy a number of concrete beams by applying a large tensile load. Each time, we write down the tensile strength of the beam from the test. We obtain the following data: 363 376 376 377 380 382 386 389 392 394 401 402 403 408 409 418 420 Assume that the tensile strength has a normal distribution, but we don't know the true mean or variance. Form a twosided interval that you are 95% sure includes the population mean. Problem 5. Again using the same data, now imagine that we are building a rather small bridge using only one concrete beam, and we are curious about its strength. Obviously, we can't destroy it to nd out, because then we can't use it for the bridge. You want to identify a design strength you can assume with 95% condence. Form one of the intervals discussed in class to do this