If 80% of Mars rovers land in former streambeds and 65% of the rovers in streambeds on Mars find historic evidence of water whereas 10% of the rovers not in streambeds do, what percent of Mars rovers find no evidence of water? Give as percentage without percent sign.

Based on statistics from a worldwide health organization in 2005 there were 30.4 million people worldwide living with a certain disease and 2.1 million deaths from the disease by 2015 the number of people living with the disease had grown to 37.3 million and 1.6 million deaths were reported find the percent change for each statistic And write any conclusion you can draw

What proportion of the general population has an IQ of 70 or less?

Three products were used in a hot summer to keep the pool chlorine level high. Each product was used in 6 pools, and there was a total of 18 pools in the experiment. The same amount of chlorine was added to each pool (A, B, or C) and the conditions such as pool size, temperature, sun exposure etc. were similar. The chlorine levels (%) were measured and recorded after 24 hours of using the products. The percentages in the table below are the percentage of the chlorine added to the pool remaining after this 24 hours. The data is as follows: A 96 56 52 66 70 60 B 44 36 34 50 40 48 с 723227 34 40 20 24 a) Find the overall mean of the chlorine level across all the pools measured, and then find the mean of the chlorine level for each product.

In a sample of 169 students, 16 said they have donated blood. What percent of the students have donated blood?

A group of 500 students take a survey about distance learning.  150 prefer distance learning.  What is the proportion of students that prefer distance learning.

If a coin is flipped 225 times and the number of Hs is 75. Compute the proportion of Hs. Round to three places.

Suppose that the result of a public opinion poll shows that just 10% of people would be willing to give up their cell phones for 1 week in exchange for $100. How many people would need to be surveyed in order to have a margin of error of ±2%?

suppose 15 percent of the computers in some university labs are defective

Suppose that the results of a survey show that 40% of people consider summer as their favorite season. How many people should be surveyed in order to have a margin of error of 4%? Round up to the nearest whole number, if necessary. In order to have a margin of error of 4%, people should be surveyed.