What is the width of a rectangle with an area of five over 8 in.² and a length of 10 inches?

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

Maurinko [17]

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.

3 0

3 years ago

A farmer wants to transport 100 cows to another farm. Each truck can carry 7cows. He has 10 trucks . How many more trucks does h

kicyunya [14]

Answer:

3 more trucks

Step-by-step explanation:

7 cows a truck and 10 trucks equals 70 cows carried. 30 more cows/10 per truck equals 3 more trucks.

7 0

3 years ago

Read 2 more answers

How do you identify the necessary information that is missing from a problem?

alexdok [17]

Answer:

It depends

Step-by-step explanation:

Identifying what is not there is always difficult. In the general case, the range of possibilities is infinite.

For relatively simple math problems, the problem statement usually gives a context and asks a question. The context will generally tell you the nature of the relationships that apply. The question will generally be answered by making use of the relationships to relate given information to requested information.

If a relationship involves 4 items, one is "unknown" (that you're asked to find), and only 2 are given, then you know the missing information is the remaining item in the relationship.

Often, you can work a problem a number of ways, so the information that is missing depends on the method you choose for working the problem.

___

In complicated multi-step problems, relationships may need to be developed, theorems proved, massive amounts of data examined, and more. In some cases, whole new areas of mathematics may need to be invented.

6 0

3 years ago

What is the approximate value for the modal daily sales?

Aleksandr [31]

Answer:

Step-by-step explanation:

Hello!

The table shows the daily sales (in $1000) of shopping mall for some randomly selected days 

Sales 1.1-1.5 1.6-2.0 2.1-2.5 2.6-3.0 3.1-3.5 3.6-4.0 4.1-4.5 

Days 18 27 31 40 56 55 23 

Use it to answer questions 13 and 14. 

13. What is the approximate value for the modal daily sales? 

To determine the Mode of a data set arranged in a frequency table you have to identify the modal interval first, this is, the class interval in which the Mode is included. Remember, the Mode is the value with most observed frequency, so logically, the modal interval will be the one that has more absolute frequency. (in this example it will be the sales values that were observed for most days)

The modal interval is [3.1-3.5]

Now using the following formula you can calculate the Mode:

$Md= Li + c[\frac{(f_{max}-f_{prev})}{(f_{max}-f_{prev})(f_{max}-f_{post})} ]$

Li= Lower limit of the modal interval.

c= amplitude of modal interval.

fmax: absolute frequency of modal interval.

fprev: absolute frequency of the previous interval to the modal interval.

fpost: absolute frequency of the posterior interval to the modal interval.

$Md= 3,100 + 400[\frac{(56-40)}{(56-40)+(56-55)} ]= 3,476.47$

A. $3,129.41 B. $2,629.41 C. $3,079.41 D. $3,123.53 

Of all options the closest one to the estimated mode is A.

14. The approximate median daily sales is … 

To calculate the median you have to identify its position first:

For even samples: PosMe= n/2= 250/2= 125

Now, by looking at the cumulative absolute frequencies of the intervals you identify which one contains the observation 125.

F(1)= 18

F(2)= 18+27= 45

F(3)= 45 + 31= 76

F(4)= 76 + 40= 116

F(5)= 116 + 56= 172 ⇒ The 125th observation is in the fifth interval [3.1-3.5]

$Me= Li + c[\frac{PosMe-F_{i-1}}{f_i} ]$

Li: Lower limit of the median interval.

c: Amplitude of the interval

PosMe: position of the median

F(i-1)= accumulated absolute frequency until the previous interval

fi= simple absolute frequency of the median interval.

$Me= 3,100+400[\frac{125-116}{56} ]= 3164.29$

A. $3,130.36 B. $2,680.36 C. $3,180.36 D. $2,664

Of all options the closest one to the estimated mode is C.

5 0

2 years ago

I WILL MARK BRAINLIEST susan was cleaning out her fridge . there are 2 gallons of milk and 4 gallons of apple juice. how many ou

FinnZ [79.3K]

Answer:

a

Step-by-step explanation:

6 0

3 years ago