Answer: 693 years
Step-by-step explanation:
Expression for rate law for first order kinetics is given by:

k = rate constant
t = time taken for decomposition = 1
= Initial amount of the reactant
= amount of the reactant left =



for half life : 

Putting in the values , we get


Thus half life of this isotope, to the nearest year is 693.
Answer:
23/7
Step-by-step explanation:
-7x+6=-17
-7x=-17-6
-7x=-23
7x=23
x=23/7
Well, you can do it these two methods⬇
1) ⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇
2 and 1/3 (which is also written as 2 1/3)
⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆
⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇⬇
Theres only one way, but if you're putting it as a decimal then you just divide 7 from 3 to get your answer
⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆⬆
•So, 7 ÷ 3 = 2.3
•And 2(3) + 1 = 7 / 3 (if that makes sense)
Answer:

Step-by-step explanation:
-The margin of error is calculated using the formula:

-We substitute the values, n=900 and ME=30 in the formula to solve for standard deviation:

Hence, the population standard deviation is 547.1125
What you would do is change all the fractions to 20ths so they have a common denominator. For 1/5, you multiply 4x5 to get 20 in the denominator. Whatever you multiply on the bottom, you must do at the top. Do that for all fractions and you would get this:
4/20 + 5/20 + 8/20= 17/20 because denominator stays the same, add the values in the numerator.
ANSWER: 17/20