Which of the following is an example of the use of a secondary data source

a: a researcher assigns different foods to two treatment groups and records the cholesterol levels of different participants after 3 months
b: a researcher interviews people about their eating habits and compares their answers and cholesterol levels
c: a researcher watches people in the cafeteria and records their eating habits then asks them to have their cholesterol tested and report the results.
d: a researcher searches the internet and finds information that relates eating habits and cholesterol levels.

Will give brainliest plz hurry lexie surveyed 4 teenagers to find out approximately how many hours, per week, they read for fun, and how many siblings they have. brooke said she reads about 10 h a week for fun, and that she has 5 siblings. celia said she has 1 brother and 1 sister and reads for fun about 3 h each week. henry said he has 2 brothers and reads for fun about 30 min each week. jude said he doesn't read for fun and has 3 brothers and 3 sisters. use this information to complete the data table. express your answers as whole numbers or decimals. name hours of fun number of siblings brooke celia __ henry jude

Ascatter plot with a trend line is shown below. which equation best represents the given data? y = x + 2 y = x + 5 y = 2x + 5

The edge of a cube was found to be 30 cm with a possible error in measurement of 0.4 cm. use differentials to estimate the maximum possible error, relative error, and percentage error in computing the volume of the cube and the surface area of the cube. (round your answers to four decimal places.) (a) the volume of the cube maximum possible error cm3 relative error percentage error % (b) the surface area of the cube maximum possible error cm2 relative error percentage error %