Answer:
The bolts with diameter less than 5.57 millimeters and with diameter greater than 5.85 millimeters should be rejected.
Step-by-step explanation:
We have been given that the diameters of bolts produced in a machine shop are normally distributed with a mean of 5.71 millimeters and a standard deviation of 0.08 millimeters.
Let us find the sample score that corresponds to z-score of bottom 4%.
From normal distribution table we got z-score corresponding to bottom 4% is -1.75 and z-score corresponding to top 4% or data above 96% is 1.75.
Upon substituting these values in z-score formula we will get our sample scores (x) as:


Therefore, the bolts with diameters less than 5.57 millimeters should be rejected.
Now let us find sample score corresponding to z-score of 1.75 as upper limit.


Therefore, the bolts with diameters greater than 5.85 millimeters should be rejected.
He has to wait 13 minutes for the 7:18 train
Answer:
C
Step-by-step explanation:
Finding the z-score:
z = (x - μ) / σ
z = (66 - 57) / 9
z = 1
Using a z-score table or calculator:
P(z < 1) = 0.8413
84.13% of 4000 is:
0.8413 (4000) = 3365.2
Rounding up to the nearest whole number, approximately 3366 students will score less than 66. Answer C.
• Expand (2a + b)²:
(2a + b)²
= (2a + b) · (2a + b)
Multiply out the brackets by applying the distributive property of multiplication:
= (2a + b) · 2a + (2a + b) · b
= 2a · 2a + b · 2a + 2a · b + b · b
= 2²a² + 2ab + 2ab + b²
Now, group like terms together, and you get
= 2²a² + 4ab + b²
= 4a² + 4ab + b² <——— expanded form (this is the answer).
I hope this helps. =)
Tags: <em>special product square of a sum algebra</em>