Answer:
a) Between 74 and 90
b) 81.86% of the scores are between 78 and 90
Step-by-step explanation:
a) According to the Empirical Rule, in a normal distribution, 95% of the data are within 2 standard deviations of the mean. Therefore, the range that 95% of the scores fall in is between 82-4(2)=74 and 82+4(2)=90.
b) The percent of scores that are between 78 and 90 is: normalcdf(lower,upper,μ,σ) = normalcdf(78,90,82,4) = 0.8185946784 ≈ 0.8186, or about 81.86% of the scores.
Answer:it is 18
Step-by-step explanation:
You do 40=2x+4 then do 40-4 and get 36 then 36/2 is 18
D: because if you take 9.50-7.50=2 you would get p=price or the price of the pen.
Hope I helped=)
Answer:

Step-by-step explanation:

Answer:
See explanation below
Step-by-step explanation:
Find the value of x in each of the following
1) x-1+5√x-1+3=0
5√x-1 = -x -2
Square both sides
25(x-1) = (-x-2)^2
25(x-1) = x^2+4x + 4
25x-25 = x^2+4x + 4
x^2 +4x + 4 - 25x + 25 = 0
x^2 - 21x + 29 = 0
x = 21±√21²-4(29)/2
x = 21±√441-116/2
x = 21±√325/2
x = 21±18.03/2
x = 21+18.03/2 and 21-18.03/2
x = 19.515 and 1.485
4) x^4-64=0
x^4 = 64
![x = \sqrt[4]{64}](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B4%5D%7B64%7D)
x = 2.83