What are the solution(s) to the quadratic equation 40

Suppose that the distribution of typing speed in words per minute (wpm) for experienced typists using a new type of split keyboa

KengaRu [80]

Answer:

a. 0.5 or 50%

b. 0.496 or 49.6%

c. 0.8185 or 81.85%

d. Yes, it would be just 0.0013 or 0.13% of probability to find a typist whose speed exceeds 105 wpm

e. 0.0252 or 2.52%

f. The qualifying speed would be 47.4 wpm.

Step-by-step explanation:

a. Let's find the z-score this way:

μ = 60 σ= 15

z-score = (x - μ)/σ

z-score = (60 - 60)/15

z-score = 0

Now, let's calculate the p value for z-score = 0, using the z-table:

p (z=0) = 0.5 or 50%

b. z-score = (x - μ)/σ

z-score = (59.9 - 60)/15

z-score = -0.01

Now, let's calculate the p value for z-score = -.0.01, using the z-table:

p (z = -0.01) = 0.496 or 49.6%

If the question were less or equal than 60, a and b would have the same answer. But in this case, the question is "less than 60 wpm".

c.

z-score = (x - μ)/σ

z-score = (45 - 60)/15

z-score = - 1

Now, let's calculate the p value for z-score = -1, using the z-table:

p (z = -1) = 0.1587

z-score = (x - μ)/σ

z-score = (90 - 60)/15

z-score = 2

Now, let's calculate the p value for z-score = 2, using the z-table:

p (z = 2) = 0.9772

In consequence,

p (-1 ≤ z ≤ 2) = 0.9772 - 0.1587 = 0.8185 or 81.85%

d. z-score = (x - μ)/σ

z-score = (105 - 60)/15

z-score = 3

Now, let's calculate the p value for z-score = 3, using the z-table:

p (z = 3) = 0.9987

In consequence,

p (z > 3) = 1 - 0.9987 = 0.0013

Yes, it would be just a 0.13% of probability to find a typist whose speed exceeds 105 wpm.

e. z-score = (x - μ)/σ

z-score = (75 - 60)/15

z-score = 1

Now, let's calculate the p value for z-score = 1, using the z-table:

p (z = 1) = 0.8413

In consequence,

p (z > 1) = 1 - 0.8413 = 0.1587

and if the two typists are independently selected, then

p = 0.1587 * 0.1587

p = 0.0252 or 2.52%

f. p = 0.2, using the z-table, the z-score is -0.84, then:

z-score = (x - μ)/σ

-0.84 = (x - 60)/15

-12.6 = x - 60

-x = -60 + 12.6

-x = - 47.4

x = 47.4

The qualifying speed would be 47.4 wpm.

8 0

3 years ago

I NEED HELP ON QUESTION B AND C ASAP.

ipn [44]

Answer:

See below

Step-by-step explanation:

Assumed the dimensions of the top and bottom parts are identical.

Since the cylindrical part has total height of 1.8 cm and the hemisphere volume is transferred to bottom part and the cone part is still full, the value of h is the difference of the total height of cylinder and full part of the top section of cylinder:

h = 1.8 cm - 0.3 cm = 1.5 cm

Find the volume of sand in the bottom part. It consists of a hemisphere and a cylinder of 1.5 cm height.

V(cylinder) = πr²h = 3.14*(2.6/2)²*1.5 ≈ 7.96 cm³
V(hemisphere) = 2/3πr³ = 2/3*3.14*(2.6/2)³ ≈ 4.6 cm³

Total sand in the bottom part:

7.96 + 4.6 = 12.56 cm³

Time taken:

12.56 / 0.05 = 251.2 seconds = 4 min 11.2 seconds

8 0

3 years ago

Evaluate each expression if a = 4.1, b = 5.7, and c=0.3. 4. a+b-c 5. 10-(a+b) 6. B- c+2

posledela

Answer:

a+b-c = 9.5

10-(a+b) = 0.2

b-c+2 = 7.4

Step-by-step explanation:

4)

Given the expression

a+b-c

a=4.1

b=5.7

c=0.3

substituting the values in the expression

a+b-c = 4.1+5.7-0.3

= 9.8 - 0.3

= 9.5

5)

Given the expression

10-(a+b)

a=4.1

b=5.7

c=0.3

substituting the values in the expression

10-(a+b) = 10 - (4.1+5.7)

= 10 - 9.8

= 0.2

6)

Given the expression

b-c+2

a=4.1

b=5.7

c=0.3

substituting the values in the expression

b-c+2 = 5.7 - 0.3 +2

= 5.4 + 2

= 7.4

7 0

3 years ago

which describes 1/8 is it a real number and rational number is it a real number and an irrational number and a natural number is

Aloiza [94]

Real numbers are all numbers found on the number line (positive, negative, fractions, square roots, whole numbers).

Rational numbers are fractions, or quotients, of two integers.

Irrational numbers are numbers with decimals that continue on (without repetition). They cannot be written as a fraction of two integers. Irrational number examples: √41, √97, √15

Natural numbers are whole, positive numbers.

Integers are whole, non-fraction numbers.

ANSWER: 1/8 is not a whole number, an integer or a natural number. It is a real and rational number (choice #1).

Hope this helps! :)

3 0

3 years ago

Find the sale price of the item. Round to two decimal places if necessary. Original price: $71.00 Markdown: 33% The sale price i

soldi70 [24.7K]

Answer:

8. $35.10

9. $59.63

10. $13.43

11. $70

12. Take the percent you pay (100-the discount) as a decimal and multiply it by the regular price.

Step-by-step explanation:

For finding the price we pay during a sale, we focus on the percent we pay. If 22% off is the sale, then we spend 78% or 100-22-78. We use this percent byb multiplying the price with a decimal. We convert percents into decimals by dividing the percent number by 100. For example, 78% divided by 100 becomes 0.78.

8. Percent off is 22%. We pay 78%=0.78.

45(0.78)=$35.10

9. Percent off is 33%. We pay 67%=0.67.

89(0.67)=$59.63

10. Percent off is 44%. We pay 56%=0.56.

23.99(0.56)=$13.43

11. Percent off is 75%. We pay 25%=0.25.

279.99(0.25)=$70

12. See explanation above.

3 0

3 years ago

Read 2 more answers

What are the solution(s) to the quadratic equation 40 - x2 = 0?