Please Answer Correctly and you must use Excel and show your workings.

3. A rail company installed new passing tracks and a centralized traffic control system on a particular rail line to reduce delays. Suppose that, before theimprovements, trains on the line were on average 12.8 minutes late. After the improvements, a consumer group monitored delays during a period of three months. For a random sample of 45 trains on the line, it found the average delay to be 6.4 minutes with a standard deviation of 7 minutes. "The improvements reduced delays by half," it claimed. Can it be concluded that the claim is true? (Use alpha=0.05) 4. A market researcher at a major clothing company that has traditionally relied on catalog mail-order sales decides to investigate whether the amount of online sales has changed. She compares the mean monthly online sales of the past several months with a historical figure for mean monthly sales for online purchases. She gets a P-value of 0.14. Explain in this context what the 14% represents