Answer:
1. 516 ppm; 2. 561 ppm
Step-by-step explanation:
1. CO₂ increase at old rate
Time = 2100 - 2010 = 90 years
Increase in CO₂ = 90 yr × (1.4 ppm/1 yr) = 126 ppm
CO₂ in 2010 = 390 + 126 = 516 ppm
At the old rate, the CO₂ concentration in 2100 will be 516 ppm.
2. CO₂ increase at new rate
Time = 2100 - 2010 = 90 years
Increase in CO₂ = 90 yr × (1.9 ppm/1 yr) = 171 ppm
CO₂ in 2010 = 390 + 171 = 561 ppm
At the new rate, the CO₂ concentration in 2100 will be 561 ppm.
You're looking for a value
such that
Because the distribution is symmetric, the value of
in either case will be the same.
Now, because the distribution is continuous, you have that
The mean for the standard normal distribution is
, and because the distribution is symmetric about its mean, it follows that
.
You can consult a
score table to find the corresponding score for this probability. It turns out to be
.
Answer:
Step-by-step explanation:
-15 times -5 = 75
-15 + -5 = -20
Sum = ADDITION SO ... 11 + 12 = 23.
