Data analysis Speech or Presentation Example | Topics and Well Written Essays - 1500 words

Data analysis - Speech or Presentation Example (iv) In a random sample of 100 students at a particular university, 60 indicated that they favoured having the option of receiving pass-fail grade for elective courses. Obtain a 90% confidence interval for the proportion of the population of students who favour pass-fail grades for elective courses. Does this confidence interval contain the value? Explain why this particular value might be of interest. (i) Suppose 16 tax returns are randomly sampled by the Australian Taxation Office from the population of 1987 tax returns with adjusted gross income between $25000 and $30000. The interest deductions (in $) claimed on the returns are as follows: In 1980 the average interest deductions for individuals in this tax bracket was $3011. Do the sample data provide sufficient evidence to conclude that in 1987 the average interest deduction claimed by taxpayers in this income bracket was different from 1980? Use. State all the assumptions you need to perform the test. Assuming that the sample comes from a normal population. Since, the population standard deviation is unknown, therefore using t-distribution to perform the test. The hypothesis test will one sample mean vs. hypothesized value two tail test. (ii) An economist claims that the unemployment rate for non-English speaking individuals in New York City is at least 30%. In a random sample of 400 non-English speaking residents of New York City, 90 are unemployed. (iii) Twenty babies are randomly selected for an experiment to determine if different brands of baby food affect a child’s weight. The babies are separated into 5 groups, and each group is fed a different diet. The weight gained in pounds by each baby after being on the diet four months is recorded in the following table: Use a 1% level of significance level to test if the type of diet affects weight gain. Clearly state the null and alternative hypotheses and state all the necessary assumptions

Fish Essay Example | Topics and Well Written Essays - 500 words

Fish - Essay Example The success of tilapia fishing has been its profitable aspect due to its omnivorous feeding habits, its rapid growth that allow high populations in the ponds, its high tolerance level allows the species to be harvested in large quantity (Halweil and Mastny, 56). The reason for tilapia farming is that its farming helps in the acquirement of Omega 6 and Omega 3 that are so important in the human body. Tilapia farming has also helped to reduce the disease occurrence of the fish species. Tilapia population in the world is around 1,500000 metric tonnes. Trout fish are a native fish of the north west America parts, but in the recent days they have been introduced into the rest of the world. The most cultivated trout are the rainbow trout due to its hardy species. It has been a successful farming because of the tolerability of the fish species in a wide range of temperatures (0-27ÌŠ C), trout fish are also farmed due to their ability to survive in fresh water. The population of trout in Britain is 16000 tonnes each year. The farming of trout in ponds and cages in the world has really helped in controlling its wild population because wild trout help in cleaning the river streams and oxygenation of the water (Halweil and Mastny, 63). Carp fish are of many different types such as common carp, grass carp among other types. Carp fish is a native fish from the Asia and Europe. Carp fish has a hurting effect on the other wild fish, this is because they interfere with the vegetation found on the sea bed, and hence other fish starve to death or migrate to other areas (Halweil and Mastny, 67). Fish farming has had a negative effect on the environment in the world. Most of the wet areas along the coast of the planets have been dried up as most of them are cleared in order to create space for putting up a fish farm. The mangrove vegetation is cut down for easy flow of water (Halweil and Mastny 2008). It is known that fish