Please help...

#1
I´m a total statics newbie and have absolutely no clue about the following exercises. I don´t know which test has to be performed to analyze the data. Could anyone please help me? :)

(1) A secretariate send their employees on IT training and want to test the effectiveness of the seminar by comparing the average times of 10 required for a typical office task. Listed below are the time in seconds before and after training for each secretary
Before training: 13.6, 13.7, 12.9, 12.2, 13.8, 13.1, 14.0, 13.9, 13.0, 13.7
After training: 12.9, 12.5, 12.0, 12.6, 12.5, 12.3, 12.6, 13.1, 12.4, 13.1
Did the training have any effect? Should the company send employees of other offices to this training as well in order to decrease working times? Answer the question at the 5% and 1% level.

(2) For the Titanic data, answer did women and children have a significantly (at 1% level) better chance of survival than males? (Tipp: test for both women and children separately)

(3) A trader compares average returns of all shares of a block of shares of the past month to find whether keeping the block pays off or not:
0.146842 0.156757 0.091255 0.063720 0.148471 -0.045436 0.150407 0.077905 0.077267 0.026454 0.090700 0.245384 0.129650 0.141617 0.039957 0.165351 0.029091 0.073473 0.189657 0.123897

(4) A marketing department is supposed to find the market share of their product. To answer this question, a survey among 720 representative people is conducted, 696 of which complete the poll with reasonable data. Among those 413 are buyers of the product. First, calculate an estimation with either the ML or Bayesian approach of the market share with 95% and 99% confidence interval. Second, test whether the market share has increased significantly at the 1 and 5% level compared to the time before their advertisement campaign, when the market share was at 55%.

(5) Before taking a job, a candidate wishes to compare the salaries at two different companies both willing to hire her. The follwing are the observed salaries:
first company: 4218.874 2323.970 4104.761 3172.519 3058.287 2386.729 4405.709 2665.709 5326.124 2993.015 5152.121 3164.876 2703.269 3837.005 2927.137 2847.995 3087.938 3063.339 4697.341 5602.379 2992.996 5052.060 4095.423 1668.059 6268.097
second company: 1888.252 2429.395 2062.037 1932.138 1788.335 2119.263 2185.819 2173.098 2391.626 1576.546 1871.540 2405.640 2470.771 1879.237 2181.048 2272.962 2174.767 1729.053 1119.993 2325.788 2112.610 2847.006 1124.272 5320.000 4785.000
Which one offers a more attractive salary?

(6) You find a list of historic gold prices in ”Historic Gold and Silver Prices.csv“. Analyse whether the average price in this timespan significantly at the 1% level exceeded USD 1375.