77, 45, 72, 56, 98, 60, 70, 89, 50, 80, 95, 70, 34, 77, 65, 70, 70, 82, 86, 86 • Part 2: What percentage of the scores are within one standard deviation of the mean (±1)? Please include the range of values for this deviation and the exact values from the data set that are included in this range.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

sweetheart, there isn't a cube below.