Answer:
approximately 27 grams
Work Shown:
Half life formula
y = A*(0.5)^(x/H)
where,
A = starting amount = 30 grams
H = half life period = 90 years
x = number of years that pass by = 12
y = amount left over after x years
Let's plug the values for x, A and H into the formula to find y
y = A*(0.5)^(x/H)
y = 30*(0.5)^(12/90)
y = 27.3516746567466
y = 27 .... rounding to the nearest whole number
c. (x + 5)(x - 7) use the FOIL method.
x² + 5x - 7x - 35
x² + (5x - 7x) - 35 collect like terms.
x² - 2x - 35
hope that helps, God bless!
Answer:
The probability that a random sample of 10 second grade students from the city results in a mean reading rate of more than 96 words per minute
P(x⁻>96) =0.0359
Step-by-step explanation:
<em>Explanation</em>:-
<em>Given sample size 'n' =10</em>
<em>mean of the Population = 90 words per minute</em>
<em>standard deviation of the Population =10 wpm </em>
<em>we will use formula</em>
<em> </em>
<em></em>
<em>Let X⁻ = 96</em>

Z = 1.898
<em>The probability that a random sample of 10 second grade students from the city results in a mean reading rate of more than 96 words per minute</em>
<em></em>
<em></em>
<em> = 1- P( Z ≤z⁻)</em>
<em> = 1- P(Z<1.898)</em>
= 1-(0.5 +A(1.898)
= 0.5 - A(1.898)
= 0.5 -0.4641 (From Normal table)
= 0.0359
<u><em>Final answer</em></u>:-
The probability that a random sample of 10 second grade students from
= 0.0359
Answer:
Step-by-step explanation:
Do 4 times 15 and add 3 then divide the denominator by the numirator