Answer:
Given that,
The number of grams A of a certain radioactive substance present at time, in years
from the present, t is given by the formula
a) To find the initial amount of this substance
At t=0, we get
We know that e^0=1 ( anything to the power zero is 1)
we get,
The initial amount of the substance is 45 grams
b)To find thehalf-life of this substance
To find t when the substance becames half the amount.
A=45/2
Substitute this we get,
Taking natural logarithm on both sides we get,
Half-life of this substance is 154.02
c) To find the amount of substance will be present around in 2500 years
Put t=2500
we get,
The amount of substance will be present around in 2500 years is 0.000585 grams
Answer:
The correct option is C. either a t test or an analysis of variance can be performed.
Step-by-step explanation:
Consider the provided information.
- The t-test, is used for whether the means of two groups are equal or not. The assumption for the test is that both groups are sampled from normal distributions with equal variances.
- Analysis of Variance (ANOVA) is a statistical method evaluating variations between two or more methods. ANOVA is used in a study to analyze the gaps between group methods.
- ANOVA is used not for specific differences between means, but for general testing.
- The chi-squared test is often used to evaluate whether there was a significant difference in one or more groups between the predicted frequencies and the observed frequencies.
Hence, Either a t test or an analysis of variance can be performed to determine whether the means of two population are equal.
Therefore, the correct option is C. either a t test or an analysis of variance can be performed.
Answer:
kevin = 8 - hope this helped
:)
Step-by-step explanation:
Kevin = 4d Kevin is 4 times as old as Daniel
Kevin = d + 6 Kevin is 6 years older than Daniel
4d = d + 6 They both equal K, so they are equal
3d = 6 subtracts D from both sides
d=6/3 = 2
If Daniel is 2 then Kevin is 4x2=8
If Daniel is 2 then Kevin is 2+6 = 8
Kevin is 8
Daniel is 2
Answer:
The ratio of girls is 24.
Step-by-step explanation:
If the total amount of swimmers is 40, you can divide it by 8 to get 5 multiples. If three of those 5's belong to the ratio of girls, the equation is 3 x 8. The answer is 24.
