Roger Sanchez

California State University - Fullerton
Teacher

Biography

I graduated from Cal State Fullerton. I'm currently a High School Math teacher.

Education

BS Mathematics
California State University - Fullerton

Educator Statistics

Numerade tutor for 4 years
554 Students Helped

Topics Covered

The Power of Algebraic Language: Unlocking Mathematical Potential
Mastering Equations and Inequalities: Your Guide to Mathematical Success
Understanding Complex Numbers: A Comprehensive Guide

Roger's Textbook Answer Videos

1

Roger's Quick Ask Videos

05:06
Intro Stats / AP Statistics

A random sample of 68 lunch customers was taken at a restaurant.
The average amount of time the customers in the sample stayed in
the restaurant was 42 minutes with a standard deviation of 11
minutes.
1) Construct 88% confidence interval for the population
mean and provide the lower and
upper bound of the confidence interval below.
2) Construct 96% confidence interval for the population
mean and provide the lower and
upper bound of the confidence interval below.

Roger Sanchez
07:49
Intro Stats / AP Statistics

Birth weights in the United States have a distribution that is
approximately normal with a mean of 3000 grams and a stand
deviation of 750 grams.
a) If one baby is randomly selected, what is the probability
that this baby will have a birth weight above 4500 g?
b) If one baby is randomly selected, what is the probably that
this baby will have a birth weight between 2500g and 4000 g?
c) One definition of a premature baby is that the birth weight
is below 2000 g. If a baby is selected randomly, find the probably
of a birth weight below 2000 g.
d) Another definition of a premature baby is that the birth
weight is in the bottom 3%. Find the birth weight that is the
cutoff between the bottom 3% and the 9%.

Roger Sanchez
04:28
Intro Stats / AP Statistics

Calculate the sample standard deviation of the quantitative data
shown. Round to two decimal places.
x
17
16
11
21
12
10
23
22
sample standard deviation =

Roger Sanchez
05:54
Algebra and Trigonometry

Use the Law of Cosines to solve the triangle. (Round your answers to four decimal places.) B = 18°35', a = 43, c = 32
A ≈ 122.6
C ≈ 38.8
b ≈ 16.7

Roger Sanchez
05:47
Intro Stats / AP Statistics

The percent of fat calories that a person in America consumes
each day is normally distributed with a mean of about 36 and a
standard deviation of 10. Suppose that one individual is randomly
chosen. Let
X = percent of fat calories.
(a) Find the z-score corresponding to 38 percent of fat
calories, rounded to 3 decimal places.
(b) Find the probability that the percent of fat calories a
person consumes is more than 38.
(c) Shade the area corresponding to this probability in the
graph below. (Hint: The x-axis is the z-score. Use your z-score
from part (a), rounded to one decimal place).
(d) Find the maximum number for the lower quarter of percent of
fat calories. Round your answer to 3 decimal places.
(e) Sketch the graph and write the probability statement.

Roger Sanchez
03:37
Intro Stats / AP Statistics

Scores for a common standardized college aptitude test are
normally distributed with a mean of 490 and a standard deviation of
115. Randomly selected men are given a Test Preparation Course
before taking this test. Assume, for sake of argument, that the
preparation course has no effect.
If 13 of the men are randomly selected, find the probability
that their mean score is at least 541.
P(M > 541) =

Roger Sanchez
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