Need help with equation

Question

The following table gives the worldwide infant mortality rates (the number of deaths per 1,000 live births) in different years since 1950.
Year 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
Infant Mortality Rate 157 141 119 104 93 87 78 70 66 62 57

(a)
Find the equation R of the linear function that best fits the data, where t is the number of years since 1950. (Round all numerical values to three decimal places.)
R =

 

(b)
Predict the worldwide infant mortality rate (per 1,000 live births) in 2021, based on the linear function. (Round your answer to one decimal place.)
deaths per 1,000 live births

 

(c)
Find the equation of an exponential function that fits the data. (Round all numerical values to three decimal places.)
R =

 

(d)
Predict the worldwide infant mortality rate (per 1,000 live births) in 2021 based on the exponential function. (Round your answer to one decimal place.)
deaths per 1,000 live births

Answer 1

(a)  R(x) = 142.091 - 1.924*X

 

(b) 2021-1950 = 71.

 

    R(71) = 5.487

 

The formula is quite tedious, and I have done it with MS Excel. But here's the website:

https://www.mathportal.org/calculators/statistics-calculator/correlation-and-regression-calculator.php

 

(c)  R(x) = 147.5569152*(0.980040851)^x

 

(d)  Again, x=2021 - 1950 = 71

 

  R(71) = 35.2611326463875

 

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