<span>The decay of 277 mg of an isotope is described by the function
A(t)= 277e-0.019t,
where t is time in years.
To find the amount left after 64 years,
We substitute t = 64 in the expression.
</span>A(t=64)= 277e-0.019(64)
or A(t=64) = 277 * e-1.216
= 277 * 0.29
= 82 mg
Answer:
a1
Step-by-step explanation:
Just add the numerators if both fractions to get: a + 1 = a1
Let <em>X</em> be the random variable representing the amount (in grams) of nicotine contained in a randomly chosen cigarette.
P(<em>X</em> ≤ 0.37) = P((<em>X</em> - 0.954)/0.292 ≤ (0.37 - 0.954)/0.292) = P(<em>Z</em> ≤ -2)
where <em>Z</em> follows the standard normal distribution with mean 0 and standard deviation 1. (We just transform <em>X</em> to <em>Z</em> using the rule <em>Z</em> = (<em>X</em> - mean(<em>X</em>))/sd(<em>X</em>).)
Given the required precision for this probability, you should consult a calculator or appropriate <em>z</em>-score table. You would find that
P(<em>Z</em> ≤ -2) ≈ 0.0228
You can also estimate this probabilty using the empirical or 68-95-99.7 rule, which says that approximately 95% of any normal distribution lies within 2 standard deviations of the mean. This is to say,
P(-2 ≤ <em>Z</em> ≤ 2) ≈ 0.95
which means
P(<em>Z</em> ≤ -2 or <em>Z</em> ≥ 2) ≈ 1 - 0.95 = 0.05
The normal distribution is symmetric, so this means
P(<em>Z</em> ≤ -2) ≈ 1/2 × 0.05 = 0.025
which is indeed pretty close to what we found earlier.
Answer:
21
Step-by-step explanation:
Answer:
p v q = x < -3 or x > 3
Step-by-step explanation:
We are given
p: x < -3
q: x > 3
and we need to find p v q
v symbols represents disjunction and in simple terms it is called "or"
So, p v q represents either p holds or q holds
So, p v q = x < -3 or x > 3
