Home » 2020 » December

# Monthly Archives: December 2020

## Confidence Interval for MEAN Normal Distribution example question

A manager at a power company monitored the employee time required to process high-efficiency lamp bulb rebates. A random sample of 40 applications gave a sample mean time of 3.8 minutes and a standard deviation of 1.2 minutes. Construct a 90% confidence interval for the mean time to process μ.

Solution to this Confidence Interval Statistics practice problem is given in the video below!

## T-Distribution Confidence Interval for MEAN example

From a random sample of size 16, one has calculated the 95% confidence interval for μ (population mean) and obtained the result (39.51, 42.49). What are the (sample mean) and s (sample standard deviation) for the sample? Assume the population is normal.

Solution to this Confidence Interval Statistics practice problem is given in the video below!

## Confidence Interval for PROPORTION Normal Distribution example problem

A telephone survey of 1,000 was taken after movie X came out in the national theater.

a) If 832 liked the movie, with what confidence can it be asserted that 83.2% ± 3% of the adult population liked this movie?

b) If the adult population in the nation is 150 million, what is the interval estimating the total number of people in the nation who liked the movie?

Solution to this Confidence Interval Statistics practice problem is given in the video below!

## Greatest Common Factor and Least Common Multiple example question

GCF(A, B) = 21

LCM(A, B) = 6(5)(72)

B = 3(72)

Find the value of A.

Solution to this Algebra GCF LCM practice problem is given in the video below!

## Least Common Multiple example word problem

What is the least number of cards that could satisfy the following three conditions?

Condition 1: If all the cards are put in 2 equal piles, there is 1 card left over

Condition 2: If all the cards are put in 3 equal piles, there is 1 card left over

Condition 3: If all the cards are put in 5 equal piles, there is 1 card left over

Solution to this Algebra Least Common Multiple practice problem is given in the video below!

## Translation Coordinates and Graph of Translated Image example question

Find the coordinates and the translated graph of A(-2, 3), B(4, -5), and C(0, 3) by following the rule of translation:

(x, y) → (x – 5, y + 6).

Solution to this Translation Geometry practice problem is given in the video below!

## Finding Coordinate RULE of Translation given Graph of Translated Image example problem

Find the coordinate rule for the translation shown in the graph below. Solution to this Translation Geometry practice problem is given in the video below!

## Dilation Formulas and Graph with Origin the Center of Dilation example question

Graph the triangle with vertices A(-2, 4), B(1, -4), C(-3, -2) and its image after dilation by scale factor k = -3. The center of dilation is the origin.

Solution to this Dilation Geometry practice problem is given in the video below!

## Dilation Formulas and Graph with Center of Dilation NOT the Origin example problem

Graph the triangle with vertices A(-2, 4), B(1, -4), C(-3, -2) and its image after dilation by scale factor k = 2. The center of dilation is the point (4, 5).

Solution to this Dilation Geometry practice problem is given in the video below!