Answer:
From what I can see of the problem, you CANNOT solve for the half-life of U 235 AND then solve for the length of time to determine the 20% decay.
U-235 half-life is 704,000,000 years. (Wikipedia)
The elapsed time formula = half-life * [log (Beginning Amount / ending amount) / log 2]
elapsed time = 7.04 x 10^8 * [log (100 % / 80%) / log 2]
elapsed time =7.04 x 10^8 * [log (1.25) / .30103]
elapsed time =7.04 x 10^8 * [0.096910 / .30103]
elapsed time = 7.04 x 10^8 * 0.321928047
elapsed time = 226,637,000 years
Step-by-step explanation:
1/20. I believe. One granola bar out of ten is 1/10 and half of a granola bar (or half of 1/10) is 1/20.
Answer:
rises to the left and rises to the right
Step-by-step explanation:
<h3>The medians does'nt support the conclusion</h3>
<em><u>Solution:</u></em>
Given that,
Robin's scores: 99, 108, 102, 107, 119
Order the number from least to greatest
99, 102, 107, 108, 119
Median is the middle value of data set
Median is 107
Evelyn's scores: 125, 137, 138, 145, 145
Order the number from least to greatest
125, 137, 138, 145, 145
Medain is 138
The median of Evelyn's scores is greater than the median of Robin's
Therefore, the medians does'nt support the conclusion.