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
defon
3 years ago
12

The distribution of the Iowa Test of Basic Skills (ITBS) vocabulary scores for 7th-grade students in Gary, Indiana is Normal wit

h a mean of 12 and a standard deviation of 3. Using the empirical rule, what percent of ITBS scores are between 3 and 12
Mathematics
1 answer:
AleksAgata [21]3 years ago
7 0

Answer:

49.85% of ITBS scores are between 3 and 12

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 12

Standard deviation = 3

The normal distribution is symmetric, which means that 50% of the scores are below the mean and 50% are below.

What percent of ITBS scores are between 3 and 12

12 is the mean

3 = 12 - 3*3

3 is three standard deviations below the mean.

By the Empirical Rule, of the 50% of the measures which are below the mean(below 12), 99.7% are within 3 standard deviations of the mean, that is, above 3.

So

p = 0.5*0.997 = 0.4985

49.85% of ITBS scores are between 3 and 12

You might be interested in
3. A jet traveled at an average speed of 681 kilometers an hour. At that rate, how far did the jet go in 7 1/4 hours?​
Burka [1]

\stackrel{mixed}{7\frac{1}{4}}\implies \cfrac{7\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{29}{4}} \\\\[-0.35em] ~\dotfill\\\\ \begin{array}{ccll} K ms&hours\\ \cline{1-2} 681 & 1\\ x& \frac{29}{4} \end{array} \implies \cfrac{681}{x}=\cfrac{1}{~~ \frac{29}{4}~~}\implies \cfrac{684}{x}=\cfrac{4}{29} \\\\\\ 19836=4x\implies \cfrac{19836}{4}=x\implies 4959=x

6 0
3 years ago
Quadratic equation has 5x+0 as a linear factor what value is a zero of the associated quadratic function.
natka813 [3]

9514 1404 393

Answer:

  x = 0

Step-by-step explanation:

The zero is the value of x that makes the linear factor zero:

  5x +0 = 0

  5x = 0 . . . . . simplify

  x = 0/5 = 0 . . . . divide by 5

The associated zero is x = 0.

7 0
3 years ago
The local supermarket buys lettuce each day to ensure really fresh produce. Each morning any lettuce that is left from the previ
jekas [21]

Given Information:

Cost price = $4

Selling price = $10

Salvage value = $1.50

Average demand = μ = 250 boxes

Standard deviation = σ = 34 boxes

Required Information:

Number of lettuce boxes = ?

Answer:

The supermarket should purchase 268 boxes  of lettuce

Step-by-step explanation:

The required number of lettuce boxes that supermarket should purchase is given by

Number of lettuce boxes = μ + (z*σ)

Where μ is the average demand of lettuce boxes, σ is the standard deviation, and z is the z-score which is given by

p = C_us/(C_us + C_os)

The z-score corresponding to probability p will be obtained.

The cost of under stocking is given by

C_us = Selling price - Cost price

C_us = $10 - $4

C_us = $6

The cost of over stocking is given by

C_os = Cost price - Salvage value

C_os = $4 - $1.50

C_os = $2.50

p = C_us/(C_us + C_os)

p = 6/(6 + 2.50)

p = 0.7058

p  = 70.58%

The z-score corresponding to 70.58% probability is approximately 0.54

Number of lettuce boxes = μ + (z*σ)

Number of lettuce boxes = 250 + (0.54*34)

Number of lettuce boxes = 250 + (18.36)

Number of lettuce boxes = 268.36

Number of lettuce boxes ≈ 268

Therefore, the supermarket should purchase 268 boxes of lettuce.

How to use z-table?

Step 1:

In the z-table, find the probability you are looking for and note down the two-digit number of the given row. (e.g 0.5, 2.2, 0.5 etc.)

Step 2:

Then look up at the top of z-table and note down the value in the column for the remaining decimal point in the range of 0.00 to 0.09.

Step 3:

Finally, add the numbers obtained from step 1 and step 2.

8 0
4 years ago
Factorise y^3- 7y+6 ​
Tatiana [17]

Answer:

(y−1)(y−2)(y+3)

Step-by-step explanation:

Factor y3−7y+6

y3−7y+6

=(y−1)(y−2)(y+3)

4 0
3 years ago
Read 2 more answers
1/9=x/7 what is x as a fraction in its simplest form
MAVERICK [17]
This is the simplest form.

8 0
3 years ago
Other questions:
  • What are the dangers of having overdraft protection?
    14·1 answer
  • A part of a circle bounded by an arc and a chord is a
    10·2 answers
  • Lauren answered 150 questions correctly on her multiple choice history final that had
    8·2 answers
  • HELP ME ASAP PLZ!!!!
    7·1 answer
  • 'A certain number divided by four, added to twice that number equals 12', all written in an equation​
    12·1 answer
  • Which set of points represents equivalent ratios and would follow the same pattern on a graph? (6, 2), (3, 1), (9, 3), (10, 2) (
    13·1 answer
  • What is the common ratio of the geometric sequence below?
    14·1 answer
  • What is the solution to this equation? 8 - 5(x - 3) = 18
    7·1 answer
  • Solve the equation and enter the value of x below.<br> x-12 = 8<br> X =
    13·2 answers
  • Fill in the blank with the correct number.
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!