# Tutor profile: Claire B.

## Questions

### Subject: Basic Math

The book you are reading for English class has 9 pages. You count the number of words on each page and come up with the following 9 values: 235, 312, 277, 264, 214, 306, 259, 289, and 298. What is the median number of words on a page? What is the average number of words on a page?

The median is the number in the middle of a list of numbers, and the average is when you add all the numbers together and divide by the number of entries. If we rearrange the numbers to be in increasing order, it is as follows: 214, 235, 259, 264, 277, 289, 298, 306, 312 The median value is 277. To calculate the average, we will do: (235 + 312 + 277 + 264 + 214 + 306 + 259 + 289 + 298) / 9 = 273

### Subject: Chemistry

Lasers are utilized in modern tattoo removal processes to lighten the appearance of unwanted tattoos. The most common tattoo removal laser utilizes light with a wavelength of 1064 nm. What is the energy (in Joules) of the laser?

Need to use the equation E=hc/lambda, where lambda is wavelength, h is Planck's constant and c is the speed of light. First, convert nm to m, then substitute the value of wavelength into the equation to solve for E. Our answer should have four significant figures. 1064 nm x (1 m / 10^9 nm) = 1.604 x 10^-6 m E = ((6.626 x 10^-34 Js)(3.0 x 10^8 m/s)) / (1.064 x 10^-6 m) = 1.868 x 10^-19 J

### Subject: Algebra

If a linear regression line has a slope of 16.2 and an intercept of 4.32, what is the value of x when y = 6.0?

Linear regression lines have the format y=mx+b, so the equation in this example is y = 16.2x + 4.32. To solve, substitute 6.0 in for y and solve for x. Our answer should have 2 significant figures based on the numbers in the original question. 6 = 16.2x + 4.32 1.68 = 16.2x x = 0.10

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