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
Goshia [24]
3 years ago
5

A normal distribution curve, where x = 70 and σ = 15, was created by a teacher using her students’ grades. What information abou

t their performances can be obtained by analyzing the curve?
Mathematics
2 answers:
quester [9]3 years ago
5 0
The curve is a normal distribution curve where x = 70 and <span>σ = 15. The variable x is the mean of the students' grades which is equal to 70. The standard deviation is 15, the actual mean is 70+-15. A normally distributed curve means that most of the students got mostly 75. </span>
alexira [117]3 years ago
4 0

The <em><u>correct answer</u></em> is:

We can conclude that 68% of the scores were between 55 and 85; 95% of the scores were between 40 and 100; and 99.7% of the scores were between 25 and 100.

Explanation:

The empirical rule tells us that in a normal curve, 68% of data lie within 1 standard deviation of the mean; 95% of data lie within 2 standard deviations of the mean; and 99.7% of data lie within 3 standard deviations of the mean.

The mean is 70 and the standard deviation is 15. This means 1 standard deviation below the mean is 70-15 = 55 and one standard deviation above the mean is 70+15 = 85. 68% of data will fall between these two scores.

2 standard deviations below the mean is 70-15(2) = 40 and two standard deviations above the mean is 70+15(2) = 100. 95% of data will fall between these two scores.

3 standard deviations below the mean is 70-15(3) = 25 and three standard deviations above the mean is 70+15(3) = 115. However, a student cannot score above 100%; this means 99.7% of data fall between 25 and 100.

You might be interested in
What is x and y? 2x-2y=-4 2x+y=11 Is there infinitely many solutions, 1 solution, or no solution? solve by elimination.
Kaylis [27]

Let's solve your system by substitution.

2x−2y=−4;2x+y=11

Rewrite equations:

2x+y=11;2x−2y=−4

Step: Solve2x+y=11for y:

2x+y=11

2x+y+−2x=11+−2x(Add -2x to both sides)

y=−2x+11

Step: Substitute−2x+11foryin2x−2y=−4:

2x−2y=−4

2x−2(−2x+11)=−4

6x−22=−4(Simplify both sides of the equation)

6x−22+22=−4+22(Add 22 to both sides)

6x=18

6x/6 = 18/6

(Divide both sides by 6)

x=3

Step: Substitute3forxiny=−2x+11:

y=−2x+11

y=(−2)(3)+11

y=5(Simplify both sides of the equation)

Answer:

x=3 and y=5

5 0
2 years ago
In a sample of 11 men, the mean height was 178 cm. In a sample of 30 women, the mean height was 167 cm. What was the mean height
Anvisha [2.4K]

Answer:

I'm pretty sure it would be 345, just add the two 178 and 167

5 0
3 years ago
Estimate 81,467<br>and the estimate 121<br>then multiply them
Roman55 [17]
81,467 to nearest hundred is 81,500
121 to nearest hundred is 100
81,500 • 100 = 8,150,000
5 0
2 years ago
Solve for x.<br> Need help, Thank you!!<br> Also, i need explanation.
babunello [35]

Answer:

7.) x = 12

9.) x = 4

Step-by-step explanation:

7.) Angle Y and Angle X both add up to 180

=> 40 + 12x - 4 = 180

=> 36 + 12x = 180

=> 12x = 180 - 36

=> 12x = 144

=> x = 12

9.) Angle W and Angle X add up to 180

=> 145 + (-1) + 9x = 180

=> 144 + 9x = 180

=> 9x = 180 - 144

=> 9x = 36

=> x = 36 / 9

=> x = 4

Hope this helps!

4 0
2 years ago
Which set of side lengths could be used<br> to form a triangle?
astra-53 [7]

Answer:

When the two shortest sides added up are larger then the longest side it can form a triangle

5 0
2 years ago
Other questions:
  • A 6 sided number cube is rolled 24 times and lands on 2 four times and on 6 three times.
    15·1 answer
  • Please help me... ASAP
    9·1 answer
  • What is the value of the function when x = 2? A set of points are plotted on a coordinate grid. The points include point 1, 2...
    8·2 answers
  • which one of following statement expresses a true proportion 3:4=9:12 b. 2:1=1:2 c. 7:9=8:9 d. 54:9=6:3
    8·1 answer
  • Find the area lying outside r=6cos(theta) and inside r=3+3cos(theta)
    6·1 answer
  • ( WILL MARK BRAINLIEST IF CORRECT)
    5·2 answers
  • Use the image to complete the equation below
    14·1 answer
  • 27 The data in the table below shows a linear relationship.
    11·1 answer
  • I need a little help here please
    12·1 answer
  • edgar purchased three cheeseburgers for 5.75 fiona purchased five cheeseburgers for 7.50 who paid less
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!