The owner of a tire company wants to determine how long a new type of tire tread will last by measuring the length of time, in days, it takes for the tire tread to reach 2 mm. Let μ = the true mean number of days it takes for the tire tread to wear to 2 mm. Which of the following sample sizes will have the least variability in the sampling distribution of the sample mean? 25
35
45
55

the correct answer is 55

Step-by-step explanation:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°