Joshua uses his thermometer and finds the boiling point of ethyl alcohol to be 75 degrees Celsius. He looks in a reference book and finds that the actual boiling point of ethyl alcohol is 80 degrees Celsius. What is his percent error?

6.25%

Step-by-step explanation:

Percent error is calculated by taking the difference of measured value and correct value divided by correct value and multiplied by 100%.

Mathematically,

Percent error = (correct value - measured value)/correct value  * 100%

in the problem given

measured value = 75 degrees Celsius

correct value = 80 degrees Celsius ( as given in reference book)

thus,

Percent error = (80 - 75)/80 * 100%

Percent error = (5/80 )* 100% = 6.25%

Percent error calculated by him is  6.25%.

We will see that the percent error in Joshua's measure is:

Pe = 6.25%

The percent error for a measure is computed as:

Where A is the accepted value and M is the measured value.

Here we have:

A = 80°C

M = 70°C

Replacing that we get:

So we can conclude that the percent error is 6.25%

If you want to learn more about percent error, you can read:

link

you cant answer this dummy

step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places