The following students measure the density of a piece of lead three times. The r

Question

The following students measure the density of a piece of lead three times. The real density of lead is actually 11.34 g/cm3. Considering all the results, which person’s results were accurate? Which were precise? Were any both accurate and precise? Calculate Daniel’s and Leah’s percent error.

A) Rachel: 11.32 g/cm3., 11.35 g/cm3., 11.33 g/cm3.

B) Daniel: 11.43 g/cm3., 11.44 g/cm3., 11.42 g/cm3.

C) Leah: 11.55 g/cm3., 11.34 g/cm3., 11.04 g/cm3.

I believe Rachel is accurate and precise, Daniel is precise and Leah is neither.

I calculated Daniel’s and Leah’s percent error to be 0.79% and 0.26% respectively.

Am I correct?

Explanation / Answer

accuracy is a measure of how close you come to a target; precision is a measure of the difference between each reading. Daniel's readings were very precise, but not very accurate. Rachel's readings exhibit good accuracy, but not as much precision. Leah, well Leah just gets a D- on her lab report.

solve for x: Y = Gm/x + r

METHOD 1: Y-r = Gm/x +r –r

(Y-r) = Gm/x

x* (Y-r) = Gm/x * x

x(Y-r) = Gm

1/(Y-r)* x(Y-r) = Gm * 1/(Y-r)

x = Gm/ (Y-r)

the shape of a quadratic relationship(E parabola) a) y = 1/x

the equation of a linear relationship (C line) b. straight line

the shape of the graph of a constant increase (B line) c) y = mx + b

the equation of a quadratic relationship (D parabola) d. y = ax 2 + bx + c

0.67
13.9
778.92
797.5

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.