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
Gala2k [10]
3 years ago
9

A data set with a mean of 34 and a standard deviation of 2.5 is normally distributed

Mathematics
1 answer:
tresset_1 [31]3 years ago
7 0

Answer:

a) z= \frac{34-34}{2.5}= 0

z= \frac{39-34}{2.5}= 2

And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %

b) P(X

z= \frac{31.5-34}{2.5}= -1

So one deviation below the mean we have: (100-68)/2 = 16%

c) z= \frac{29-34}{2.5}= -2

z= \frac{36.5-34}{2.5}= 1

For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%

Step-by-step explanation:

For this case we have a random variable with the following parameters:

X \sim N(\mu = 34, \sigma=2.5)

From the empirical rule we know that within one deviation from the mean we have 68% of the values, within two deviations we have 95% and within 3 deviations we have 99.7% of the data.

We want to find the following probability:

P(34 < X

We can find the number of deviation from the mean with the z score formula:

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

And replacing we got

z= \frac{34-34}{2.5}= 0

z= \frac{39-34}{2.5}= 2

And we want the probability from 0 to two deviations above the mean and we got 95/2 = 47.5 %

For the second case:

P(X

z= \frac{31.5-34}{2.5}= -1

So one deviation below the mean we have: (100-68)/2 = 16%

For the third case:

P(29 < X

And replacing we got:

z= \frac{29-34}{2.5}= -2

z= \frac{36.5-34}{2.5}= 1

For this case below 2 deviation from the mean we have 2.5% and above 1 deviation from the mean we got 16% and then the percentage between -2 and 1 deviation above the mean we got: (100-16-2.5)% = 81.5%

You might be interested in
Tom read 20 books, 12 magazines, and 18 newspaper articles last year.
neonofarm [45]

Answer: 24% of the books read are magazine

Step-by-step explanation:sum of the books read is 20+12+18=50 books.

Therefore 12 of the books are magazine.

Then, 12 of 50 =24%( 12÷50)× 100/1 = 24%

8 0
3 years ago
Read 2 more answers
Solve using the quadratic formula. Show all work. Write each solution in simplest form. No decimals.
alexira [117]

Answer:

Option B

Step-by-step explanation:

Given quadratic equation is,

12a² + 9a + 7 = 0

By comparing this equation with standard quadratic equation,

hx² + kx + c = 0

h = 12, k = 9 and c = 7

By using quadratic formula,

a = \frac{-k\pm\sqrt{k^2-4hc}}{2h}

  = \frac{-9\pm\sqrt{9^2-4(12)(7)}}{2(12)}

  = \frac{-9\pm\sqrt{81-336}}{2(12)}

  = \frac{-9\pm\sqrt{-255}}{24}

  = \frac{-9\pm i\sqrt{255}}{24}

a = \frac{-9+ i\sqrt{255}}{24},\frac{-9- i\sqrt{255}}{24}

Therefore, Option B will be the correct option.

3 0
3 years ago
Evaluate (ab)^2 for a=4 and b=3. <br>A. 81<br>B. 144<br>C. 24<br>D. 36
worty [1.4K]
Substitute the number for the appropriate variables and solve
(ab)^2
(4×3)^2
(12)^2
12×12
144
Your answer is B.144
8 0
3 years ago
What times what equals 30 but add to get 40?
musickatia [10]
Lets call those two unknown numbers a, b and write the info in the problem as equations:
a*b = 30
a + b = 40
lets solve for a in the second equation and substitute in the first:
<span>a + b = 40
</span>a = 40 - b
therefore:
<span>a*b = 30
</span>(40 - b)b = 30
40b - b^2 = 30
b^2 - 40b + 30 = 0
if we apply the general quadratic equation to solve we have:
b = (40 +- √(1600 - 120))/2
b = (40 +- √(1480<span>))/2
</span>b = (40 +- 38.47)/2
There are two solutions:
<span>b1 = (40 + 38.47)/2
</span><span>b1 = 39.24
b2 = (40 - 38.47)/2
</span>b2 = 0.765
lets use the second solution <span>b2 = 0.765, and substitute in the first equation to find a:
</span><span>a*b = 30
</span>a*0.765 = 30
a = 30/0.765
a = 39.216
so the numbers are 39.216 and 0.765
5 0
3 years ago
Read 2 more answers
Please help! Here's the question. I really need it.
Korvikt [17]
Let’s first cut/separate this figure into two shapes: rectangle and a triangle

The area of the rectangle: 9 • 2 = 18
The area of the triangle: 1/2 • 8 • 4 = 16
The total area: 18 + 16 = 34
He needs 34 m square of grass
5 0
3 years ago
Other questions:
  • A,e,i,ou in description method<br>​
    9·1 answer
  • Convert the following unsigned binary number to unsigned decimal.<br><br> 110011.101
    9·1 answer
  • How do you solve equations like this: 7 5/6? can someone explain it? <br> (7 5/6 is just an example)
    10·2 answers
  • Select the linear equation represented in the graph.
    10·1 answer
  • Can someone please help me out with these questions?
    14·1 answer
  • (3 1/4 + 2 5/6) + 1 3/4<br><br>​
    14·1 answer
  • 2v+7=3<br><br> Help me out <br><br><br> I’m dating vinnie hacker
    12·2 answers
  • I really need help ASAP
    10·1 answer
  • Yooo I just had MAD diarrhea D:
    15·1 answer
  • How to reciprocate a whole number ​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!