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
zavuch27 [327]
3 years ago
15

A science teacher gives a test with 15 questions. This teacher is a hard grader. The teacher assigns points in the following man

ner: a correct answer =+1 point, an incorrect answer =−1 point, no answer =0 points. So scores on the test could range from +15 to −15. The teacher’s assistant calculates the standard deviation for scores on the test and reports SD =−2.3. What do we know?
- The standard deviation was calculated incorrectly.
- Most students received negative scores.
- Most students scored below the mean.
- There is an outlier that has a negative value close to -15.
Mathematics
1 answer:
ASHA 777 [7]3 years ago
6 0

Answer:  The standard deviation was calculated incorrectly.

Step-by-step explanation:

  • The standard deviation measures the dispersion of the data values from the mean value.

It cannot be negative , because it is the square root of the variance .

We add all squared deviations from the data points away from the mean and (then divide it by the number of data values) to evaluate variance.

Since , any squared number cannot give a negative result.

⇒ Standard deviation cannot be negative.

⇒The standard deviation was calculated incorrectly.

Rest other things (given in options) can not be interpreted on the basis of given information.

You might be interested in
Hello, this is math and I need help ❤️ pls and ty ONLY SERIOUS ANSWERS
Greeley [361]

The bicycle with a 30-inches diameter rolls approximately 28.8 more than a tire with the diameter with 21-inches.

<u><em>How to solve:</em></u>

  • First use the formula: C = 3.14d
  • Replace the d value with 30 and solve the equation:

C = 3.14 x 30    ⇒   94.2477796077

  • Then solve the equation again but 21 as the d value:

C = 3.14 x 21     ⇒   65.9734457254

  • Then subtract 65.9734457254 from 94.2477796077 to get the approx. answer of 28.8

3 0
2 years ago
Why is my dad so mean to me?
Vladimir79 [104]
To be honest there are lots of different reasons. You might want to try and talk to him to let him now how he is making you feel.
6 0
2 years ago
Read 2 more answers
Help me with this question
frosja888 [35]

A linear equation in the form y = mx + c has slope m Any line parallel to 3x + 9y = 5 has the same slope 3x + 9y = 5 → 9y = -3x + 5 → y = (-3/9)x + 5/9 → y = -⅓x + 5/9 & So it’s 10 and 0

7 0
3 years ago
Read 2 more answers
There are 30 seventh grade students in the cafeteria. In a representative sample of 25 students, there are 14 girls. Estimate th
Basile [38]

Answer:

17 i think

Step-by-step explanation:

7 0
3 years ago
A book exhibition was held for four days in a schoolthe number of tickets sold at the counter on the first secend third and four
bija089 [108]

Answer:

7707 tickets

Step-by-step explanation:

From the question we know that:

the number of tickets sold at the counter on

First day = 1094 tickets

Second day = 1812 tickets

Third day = 2050 tickets

Fourth day = 2751 tickets

The total number of tickets sold on all the four days is calculated as:

(1094 + 1812 + 2050 + 2751)tickets

= 7707 tickets

7 0
3 years ago
Other questions:
  • Please answer this question!!<br><br>thanks xx
    5·1 answer
  • Solve this equation<br> c<br> \/3=6 1/7
    10·1 answer
  • Which point would be a solution to the system of linear inequalities ?
    13·1 answer
  • A. Sam purchased 3 games for $140 after a discount of 30%. What was the original price?
    6·1 answer
  • Can someone explain this to me pweaseee
    14·1 answer
  • List 3 observations from your data.<br> 1. <br> 2. <br> 3.
    11·1 answer
  • NEED HELP WAITH MATH HOMEWORK ASPA PLZ HELP ME RN thank you
    5·1 answer
  • Martin is two years older than Reese, and the same age as Lee. If Lee is 12, how old is Reese? but in algebraic form
    11·1 answer
  • Please answer both please please I’ll give brainly
    5·1 answer
  • Aaron’s mother purchases a new computer for $1750. If she claims a linear depreciation (loss of value) on the computer at a rate
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!