2.) Proportions On April 15th, 1912, the R.M.S. Titanic sank into the North Atlantic Ocean, resulting in the loss of more than 1,500 passengers and crew. Below is a table which summarizes the total number of passengers and the number of survivors for the crew, first-, second-, and third-class. Find the proportion of survivors by type of service (crew, first, second, third). Test the hypothesis at the 95% confidence level that the proportion of first-class survivors is the same as .50. What do you calculate for the test-statistic? What is the critical statistic? What is the conclusion of your hypothesis test?

In politics, marketing, etc. we often want to estimate a percentage or proportion p. One calculation in statistical polling is the margin of error - the largest (reasonble) error that the poll could have. For example, a poll result of 72% with a margin of error of 4% indicates that p is most likely to be between 68% and 76% (72% minus 4% to 72% plus 4%).   In a (made-up) poll, the proportion of people who like dark chocolate more than milk chocolate was 39% with a margin of error of 1.3%. Describe the conclusion about p using an absolute value inequality.   The answer field below uses the symbolic entry option in Mobius. That lets you type in a vertical bar | to represent absolute values. Also, when you type in  <  and then =, the symbolic entry option will automatically convert that to  ≤ . In the same way, if you type in  >  and then =, the symbolic entry option will automatically convert that to  ≥.   Be sure to use decimal numbers in your answer (such as using 0.40 for 40%).

eight out of 10 dentists prefer whitening toothpaste. what is the ratio of dentists who do not prefer whitening toothpaste to those who do?

Suppose that Ford vehicles make up 20% of the U.S. vehicles market. Suppose also that 8% of U.S. vehicles are Ford’s and trucks (that is, are Ford trucks). What proportion of Ford vehicles are a truck?

The average grade for a group of students in a statistics exam was 85 points, with a standarddeviation of 3 points.a. What proportion of students have at least 80 points on the exam? b. What proportion of students have less than 80 points on the exam?

There are 435 seats in a​ nation's House of Representatives. The number of representatives per state is calculated using a statistical formula determined by​ law, but allocation is roughly proportionate to population. In​ 2010, the​ nation's population was estimated to be 309.1 million. The​ state's population was estimated at 26.1 million. How many representatives would you expect to be assigned to the​ state? Suppose the state actually has 34 representatives. Compare this with the expected number of representatives from the state.

A biologist wants to estimate proportion of humans who have a certain gene. He wants to be 95% confident that the true proportion is within 5% of the sample proportion. What should his sample size be? Select one: а. 385 b. More information is required. C. 1537 d. 384 e. 96

Suppose Maureen turns in a late vote for giraffe.What is the new ratio of giraffe votes to rabbit votes.