Today,uranium Contains $0.72 \%$ $235 _ { U }$ (Half-Life = 0

question 155

Multiple Choice

Today,uranium contains $0.72 \%$ $235 _ { U }$ (half-life = 0.70 billion years) and $99.28 \%$ $\ { 238_ U }$ (half-life = 4.5 billion years) .At a time 1.9 billion years ago,what was the fraction of $235_ { U }$ in uranium?

• A)3.53%
• B)4.72%
• C)4.90%
• D)6.76%

Understand how dimensions and shapes are accurately represented and described in technical drawings.

Understand the concept of scale in drawings and its applications.

Identify and apply the significance of a 1:1 scale in technical drawings.

Recognize alternative elements that can substitute a title block in drawings.

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Definitions:

Judgment Sampling

A nonprobability method of sampling whereby elements are selected for the sample based on the judgment of the person doing the study.

Cluster Sampling

A probability sampling method in which the population is first divided into clusters and then a simple random sample of the clusters is taken.

Simple Random Sampling

A sampling method where each member of the population has an equal chance of being selected, ensuring unbiased representation.

Stratified Simple Random Sampling

A sampling method that divides a population into smaller groups or strata and then selects random samples from each stratum.