Step-by-step explanation:
The plumber's daily earnings have a mean of $145 per day with a standard deviation of
$16.50.
We want to find the probability that the plumber earns between $135 and
$175 on a given day, if the daily earnings follow a normal distribution.
That is we want to find P(135 <X<175).
Let us convert to z-scores using

This means that:

We simplify to get:

From the standard n normal distribution table,
P(z<1.82)=0.9656
P(z<-0.61)=0.2709
To find the area between the two z-scores, we subtract to obtain:
P(-0.61<z<1.82)=0.9656-0.2709=0.6947
This means that:

The correct choice is C.
Answer:
Step-by-step explanation:
Let's write a system of equations. I'm going to call them w, x, y, and z.
w = 4x (because m∠1 is 4 times m∠2)
w + x = 90 (bc ∠1 and ∠2 are complementary, meaning they add up to 90)
w = y (bc ∠1 and ∠3 are vertical angles, meaning they are equal)
y + z = 180 (bc ∠3 and ∠4 are supplementary, meaning they add up to 180)
When we substitute w=4x into the second equation, we get 5x=90 → m∠2 = 18°. Since w=4x, m∠1 = 18*4 = 72°. Since w=y, m∠3 = 18°. Finally, because y+z=180, m∠4 = 180-18 = 162°. Hope this helps!
We are trying to find the average speed of the plane, which is mph, or
. Using proportions, we can find the average speed of the plane in mph:

- Use the information from the problem to create a proportion. Remember that we are looking for mph, so we will call that
.

- Multiply the entire equation by


- Divide both sides of the equation by
to clear both sides of the mile unit
The average speed of the plane is 300 mph.
Answer:
B
Step-by-step explanation:
2.3 is being cancelled out.
40. m∠2=148° m∠4=148°
41. ∠2 and ∠5
42. ∠1 and ∠2
43. ∠3 and ∠5
Sorry, I don't know how to do the rest, but I hope this helps!