Mastering Modal Verbs: Can, Could, Must, Mustn’t, and More

Could – Could – Manage to – Managed to

Use

We use could as the past tense of can to talk about general abilities in the past.

  • I could speak Italian really well when I lived in Venice.
  • He could walk when he was only 8 months old.
  • I could do the Times crossword ten years ago, but I can’t nowadays. I’m getting too old.
  • I could run much faster when I was 20.
  • I could read when I was only four.
  • When I was young, I could run fast, but now I cannot.
  • When I was in school, I could do a handstand, but now I’m too old.
Read More

Comprehensive Guide to Transforming Functions: Quadratic, Rational, Cubic, and More

Transformations of Functions

Quadratic Function:

The graph of the basic quadratic function Y=x^2 can be transformed using the following parameters:

g(x) = af(b(x+c)) + d

  • a:
    • a > 1: Vertical stretch by a factor of ‘a’.
    • 0 < a < 1: Vertical compression by a factor of ‘a’.
    • a = -1: Vertical reflection across the x-axis.
  • b:
    • b > 1: Horizontal compression by a factor of 1/b.
    • 0 < b < 1: Horizontal stretch by a factor of 1/b.
    • b = -1: Horizontal reflection across the y-axis.
  • c:
    • c > 0: Horizontal shift
Read More

A Comprehensive Guide to Measurement, Finance, and Geometry

MEASUREMENT AND STATISTICS

Accuracy and Precision

Accuracy: How close a measured value is to the actual value.

Precision: The smallest measurement possible on a measuring tool.

Measures of Central Tendency

Mean: Average (sum of all values divided by the total number of values).

Median: Middle value when data is arranged from least to greatest.

Mode: Most frequent value.

Trimmed Mean: Mean calculated after discarding a certain percentage of the highest and lowest values.

Weighted Mean: Mean calculated by

Read More

Statistical Hypothesis Testing and Confidence Intervals: A Comprehensive Analysis

1. Analyzing Beats Per Minute in Dance Songs

Hypotheses and Parameter

The parameter of interest is μ = mean beats per minute for all dance songs.

  • H0: μ = 120.5 beats per minute
  • Ha: μ > 120.5 beats per minute

T-Procedure Validity

Even with a slightly skewed distribution of beats per minute, the t-procedure remains valid due to its robustness to deviations from normality.

Test Statistic and P-value

Assuming necessary assumptions are met, the test statistic and P-value are calculated using a t-test (

Read More

Comprehensive Guide to Transforming Mathematical Functions

Transformations of Quadratic Functions

The general form of a quadratic function is:

g(x) = af(b(x + c)) + d

This formula describes how to transform the graph of the basic quadratic function y = x². Let’s break down each parameter:

Vertical Transformations

  • a > 1: Vertical Stretch: The graph is stretched vertically by a factor of a. For example, if a = 2, the graph is twice as tall.
  • 0 < a < 1: Vertical Compression: The graph is compressed vertically by a factor of a. For example, if a = 0.5, the
Read More

Statistics Cheat Sheet: Key Concepts and Formulas

Find the probability that exactly four of the sampled people own a tablet computer. We input 15 for n, .3 for p, and 4 for xbinompdf(15,.3,4) 15 is sample size .30=30% || To compute P(x), select poissonpdf and enter the values for λt and x separated by commas and press ENTER. || To compute P(Less than or equal to x), select poissoncdf and enter the values for λt and x separated by commas and press ENTER. || Let A and B be events with P(A) = 0.7, P(B) = 0.4, and P(B|A) = 0.2. Find P(A and B)

Read More