Mr. Whittaker’s science class uses tide gauges to measure annual variations in water levels at different parts of a river, and then compares those variations to the average annual trend.

Matea recorded that the water level in one part of the river fell 1.05 millimeters per year for 2.48 years.

Which number represents the rate at which the water level fell? -1.05mm/year

Which number should the rate be multiplied by to find the total variation in water level?

2.48 years

that's the correct answer ^
This data will be compared to the average annual trend, which shows the water level rising 1.8 mm/year.

Which number represents the rate at which the water level fell?

Which number should the rate be multiplied by to find the total variation in water level?

a) Which number represents the rate at which the water level fell? -1.05mm/year

b) Which number should the rate be multiplied by to find the total variation in water level?

2.48 years

Step-by-step explanation:

Total variation in water level is calculated as the rate at which the water level fell multiplied by number of years are which the water level fell.

Mathematically = Rate at which the water level fell(mm/year) × number of years are which the water level fell (years).

Total variation in water levels can be caused by changes in climate conditions or by human activity.

Hence, for the question above,

rate at which the water level fell is

given as -1.05mm/year and the number that the rate be multiplied by to find the total variation in water level is 2.48 years.

step-by-step explanation:

step-by-step explanation:

i found the life tables for the year 2012. 

life table of males at age 30. probability of dying between ages x and x+1

total population:  

29–30 . . . . . . . . . . . . 0.001030

30–31 . . . . . . . . . . . . 0.001061

males:  

29–30 . . . . . . . . . . . . 0.001420

30–31 . . . . . . . . . . . . 0.001448

white population

29–30 . . . . . . . . . . . . 0.001005

30–31 . . . . . . . . . . . . 0.001037

white males

29–30 . . . . . . . . . . . . 0.001372

30–31 . . . . . . . . . . . . 0.001399

non hispanic white population

29–30 . . . . . . . . . . . . 0.001083

30–31 . . . . . . . . . . . . 0.001116

non hispanic white males

29–30 . . . . . . . . . . . . 0.001477

30–31 . . . . . . . . . . . . 0.001503

jacob, non hispanic white male. 30 years old.

probability that jacob lives to be 30 years old. 

since the given probabilities are probabilities of dying, i think we simply subtract it from 1 to get the probability of living. we will use the probability of non hispanic white male.

                                          probability of living to be 30 y.o.

29 - 30 : 1 - 0.001477 = 0.998523

30 - 31 : 1 - 0.001503 = 0.998497