A battery manufacturer is interested in thelifetime of its products. Thirty batteries are tested until they fail. The times to failure (in hours) are given below.
41.3 21.1 35.6 13.5 4.2 15.8
5.5 5.8 33.6 18.6 24.3 18.1
3.5 8.4 4211 9.4 10.6 8.9 13.7 19.6 9.2 5.9 19.4 24.2 27.3 30.6 29.4 18.0 32.8 1.1.6
a) The manufacturer claims that 50% of its batteries last longer than 20 h. Describe how your graph shows
whether or not this is true.

in if you ask questions, the points are taken from your total and given to the one who answered it..

so if i have 30 points and i ask a question for 5 points, then when someone asks a question i will lose 5 points and the answerer earns 5

happy to

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