Suppose that a travel bureau claims that the trees in a forest are 83 feet tall on average, with a standard deviation of 0.2 feet. if you took a sample of 64 trees, which of the following mean heights would be outside the 95% confidence interval?

a. 83.2 feet
b. 83.4 feet
c. 83.6 feet
d. 82.8 feet

Explanation:

Given mean = 84,

Standard deviation = 2,

Sample 64,  

95% confidence interval: z = 1.96

Applying empirical rule , means that 95% of data fall within two standard deviations.

ME = = 0.49

Rounding this to 0.5

CI =  83.5< mean < 84.5

Outside of this range=  x ≤ 83.5  and ≥  84.5

i think it is 18

step-by-step explanation:

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