Answer:
80 screws
Step-by-step explanation:
25(4)-20
100-20
80
To find equivalent expressions,
distribute the first one and
factor the second one.
Answer:
Between 12.614 years and 16.386 years
Step-by-step explanation:
Given that:
Mean age (μ) = 14.5 years, standard deviation (σ) = 4.6 years, number o sample (n) and the confidence interval (c) = 90% = 0,9
α = 1 -c = 1 -0.9 = 0.1
![\frac{\alpha }{2} = \frac{0.1}{2} = 0.05](https://tex.z-dn.net/?f=%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%20%3D%20%5Cfrac%7B0.1%7D%7B2%7D%20%3D%200.05)
The z score of
is the same as the z score of 0.45 (0.5 - 0.05). This can be gotten from the probability distribution table. Therefore:
![z_{0.05}=1.64](https://tex.z-dn.net/?f=z_%7B0.05%7D%3D1.64)
The margin of error (e) =
= ![1.64*\frac{4.6}{\sqrt{16} }=1.886](https://tex.z-dn.net/?f=1.64%2A%5Cfrac%7B4.6%7D%7B%5Csqrt%7B16%7D%20%7D%3D1.886)
The interval = μ ± e = 14.5 ± 1.886 = (12.614 ,16.386)
Answer:
Well if you put -4 where x is.. you still do get the answer of 20.
So that is correct.
Step-by-step explanation:
Answer:
Step-by-step explanation:
if you've any doubt just ask :)