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Can someone give me a null hypothesis and alternative for them?
THANKS! :)

casein painting, milk, is a fast drying, water-soluble medium used by artists. It generally has a sticky consistency, but can be diluted with water to the degree that corresponds to a particular artist style and the desired result. It can be used on canvas panels, illustration boards, paper, wood and hardboard. Because the dried paint film is inflexible and fragile, it should not be applied in heavy impasto on flexible substrates such as canvas. casein painting was reworked, and can be used for underlayment. It dries quickly usually a matte medium to finish.A casein painting is to take some skim milk, cottage cheese and the first wash all the milky liquid. Pieces of casein left behind are then dissolved by adding in a saucepan with water and a little ammonia. The ammonia should be preferably in the form of ammonium carbonate. As the mixture is stirred while it heats up and begins to foam lumps dissolve. Do not boil, but just keep on the boil, stirring to stop frothing. Cool the syrup to the bottom and is the medium term. It will keep in refrigerator for about four days.