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
zvonat [6]
3 years ago
13

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.3. (Round your ans

wers to four decimal places.)
(a) If the distribution is normal, what is the probability that the sample mean hardness for a random sample of 12 pins is at least 51?
Mathematics
1 answer:
Maurinko [17]3 years ago
3 0

Answer:

0.0039 is the probability that the sample mean hardness for a random sample of 12 pins is at least 51.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 50

Standard Deviation, σ = 1.3

Sample size, n = 12

We are given that the distribution of hardness of pins is a bell shaped distribution that is a normal distribution.

Formula:

z_{score} = \displaystyle\frac{x-\mu}{\sigma}

Standard error due to sampling =

=\dfrac{\sigma}{\sqrt{n}} = \dfrac{1.3}{\sqrt{12}} = 0.3753

P(sample mean hardness for a random sample of 12 pins is at least 51)

P( x \geq 51) = P( z \geq \displaystyle\frac{51 - 50}{0.3753}) = P(z \geq 2.6645)

= 1 - P(z < 2.6645)

Calculation the value from standard normal z table, we have,  

P(x \geq 51) = 1 - 0.9961= 0.0039

0.0039 is the probability that the sample mean hardness for a random sample of 12 pins is at least 51.

You might be interested in
The radius of a right circular cone is increasing at a rate of 1.4 in/s while its height is decreasing at a rate of 2.8 in/s. At
zepelin [54]

Answer:

34191.7πin³/sec

Step-by-step explanation:

Volume of circular come = 1/3pi x r² x h

When we differentiate this formula we have

dv/dt = 1/3π[r²dh/dt + 2rhdr/dt]

We have the following information

r = 138

H = 143 inch

dr/dt = 1.4

dh/dt = -2.8

When we plug into the formula

1/3π[130² x -2.8 + 2x138x143x1.4]

= 34191.7πin³/sec

7 0
3 years ago
Very buys a basket of mangoes that is priced $14 before tax. ​ ​The sales tax is 6%. ​ ​What is the total price Avery pays for t
igor_vitrenko [27]

Answer:

Avery needs to pay $14.84

Step-by-step explanation:

When there's a tax we need to sum the original value of the product with the tax's value. To find the amount of money Avery needs to pay in taxes we can apply a rule of three as shown below:

\frac{14}{x} = \frac{100}{6} \frac{\%}{\%}

Where "x" is the tax value, and $14 represents 100%, since it's the value used to calculate the tax. We have:

x = \frac{14*6}{100}\\x = \frac{84}{100}\\x = 0.84

The value to be paid is the product value plus the tax, therefore:

\text{paid} = 14 + 0.84 = 14.84

Avery needs to pay $14.84

6 0
3 years ago
Which line best represents the line of best fit for this scatter plot? (5 points)
Bogdan [553]
Line Q, you always want the line that has as many dots on it as possible!! :)
7 0
3 years ago
Which answer is a graph for the inequality x&gt;2
seropon [69]
Show me the answers, then i'll help
6 0
3 years ago
Which one is greater -0.00001940 or 0.00005
Hunter-Best [27]
Second 1 because it isn't negative
7 0
3 years ago
Read 2 more answers
Other questions:
  • the English alphabet contains 2 more than twice as many letters as the Hawaii alphabet how many letters are there in the Hawaii
    8·2 answers
  • If one side of a square measures 6 units,<br> what is its area?
    11·2 answers
  • Select the solutions to the following inequality: |x| &lt; 7
    6·1 answer
  • What is 31,084.5 expanded notation
    14·1 answer
  • The figure shown is made up of 16 equally sized squares. Four of the squares are shaded and 12 are not.
    10·1 answer
  • A committee of 4 people is chosen from 8 women and 8 men. How many different committees are possible that consist of 2 women and
    5·1 answer
  • The amount of chlorophyll in a leaf changes based on outside temperature. What's the independent variable in the situation?
    11·1 answer
  • Which function is represented by the graph?
    6·2 answers
  • Can someone help plss
    8·1 answer
  • Solve the equation -3(x-14)+9x=6x+42. Does the equation have one solution, no solution, or infinitely many solutions?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!