1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Kipish [7]
3 years ago
12

Arsenic is a compound that occurs naturally in very low concentrations. Arsenic blood concentrations in healthy adults are Norma

lly distributed with mean =3.2 micrograms per deciliter (ug/dl) and standard deviation sigma = 1.5. What is the range of arsenic blood concentrations corresponding to the middle 90% of healthy adults?
Mathematics
1 answer:
DENIUS [597]3 years ago
5 0

Answer:

0.7325 to 5.6675 ug/dl

Step-by-step explanation:

The middle 90% will be 45% above the mean and 45% below the mean.  This means

0.5-0.45 = 0.05 and

0.5+0.45 = 0.95

We use a z table.  Look in the cells; find the values as close to 0.05 and 0.95 as we can get.

For 0.05, we have 0.0505 and 0.0495; since these are equidistant from 0.05, we use the value between them.  0.0505 is z=-1.64 and 0.0495 is z=1.65; this gives us z=-1.645.

For 0.95, we have 0.9495 and 0.9505; since these are equidistant from 0.95, we use the value between them.  0.9495 is z = 1.64 and 0.9505 is z=1.65; this gives us z = 1.645.

Now we use our z score formula,

z=\frac{X-\mu}{\sigma}

Our two z scores are 1.645 and -1.645; our mean, μ, is 3.2; and our standard deviation, σ, is 1.5:

1.645=\frac{X-3.2}{1.5}

Multiply both sides by 1.5:

1.5(1.645)=\frac{X-3.2}{1.5}\times 1.5\\\\2.4675 = X-3.2

Add 3.2 to each side:

2.4675+3.2 = X-3.2+3.2

5.6675 = X

-1.645=\frac{X-3.2}{1.5}

Multiply both sides by 1.5:

1.5(-1.645)=\frac{X-3.2}{1.5}\times 1.5\\\\-2.4675=X-3.2

Add 3.2 to each side:

-2.4675+3.2 = X-3.2+3.2

0.7325 = X

Our range is from 0.7325 to 5.6675.

You might be interested in
30. (14 letters) The process of changing one unit of measure to another.
Georgia [21]
Unit conversion
taxable income
7 0
3 years ago
Read 2 more answers
Complete the statement using always, sometimes, or never. A rectangle is __________________ a rhombus.
Lesechka [4]
Hi!

A rectangle can sometimes be a rhombus if it has sides of all equal lengths. If a rectangle was a rhombus, it would also be a square. Furthermore, a square is always a rhombus.

Hope this helps! :)
7 0
3 years ago
Directed line segment has endpoints P(– 8, – 4) and Q(4, 12). Determine the point that partitions the directed line segment in a
larisa86 [58]

Answer:

Point (1,8)  

Step-by-step explanation:

We will use segment formula to find the coordinates of point that will partition our line segment PQ in a ratio 3:1.

When a point divides any segment internally in the ratio m:n, the formula is:

[x=\frac{mx_2+nx_1}{m+n},y= \frac{my_2+ny_1}{m+n}]

Let us substitute coordinates of point P and Q as:

x_1=-8,

y_1=-4

x_2=4

y_2=12

m=3

n=1

[x=\frac{(3*4)+(1*-8)}{3+1},y=\frac{(3*12)+(1*-4)}{3+1}]

[x=\frac{12-8}{4},y=\frac{36-4}{4}]

[x=\frac{4}{4},y=\frac{32}{4}]

[x=1,y=8]

Therefore, point (1,8) will partition the directed line segment PQ in a ratio 3:1.

   

7 0
2 years ago
What number is equivalent to 3/4 b-2/3 b =-9
Shtirlitz [24]
Hi,

b =  - 9 \\ \frac{3}{4}  \times b -  \frac{2}{3}   \\ 0.75 \times  - 9 - 0.67 \\  - 6.75 - 0.67 =   - 7.42

Answer: -7.42

Hope this helps.
r3t40
5 0
3 years ago
For example #1 what is the solution
Alex73 [517]

Answer: what is example 1

Step-by-step explanation: what is it

3 0
3 years ago
Other questions:
  • HELP!!!!!!!!!! <br> What is the value of h in <br> 13h=52<br> h=
    5·2 answers
  • Write an equation of a line through (-1,1) and (0,4) using slope intercept and point slope intercept
    5·1 answer
  • A school receives a shipment of books. There are 60 cartons, and each carton weighs 42 pounds. The school's elevator can hold 22
    9·1 answer
  • What kind of construction is it??
    9·1 answer
  • What is the value of x in the diagram?
    6·1 answer
  • The diameter of a circle is 18m. Eugene claims that the circumstances of the circle is 113.04m. What is the circumference of the
    9·1 answer
  • The polygons in each pair are similiar help find the missibg length???
    5·1 answer
  • Solve it : x² *dy/dx = -2y
    5·1 answer
  • Write the following numbers in order of size start with the smallest. 0.32 0.4 0.35 0.309
    11·1 answer
  • ) A car leaves a town at 30 miles per hour. How long will it take a second car traveling at 38 miles per hour to catch the first
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!