Two processes in a manufacturing line are performed manually: operation A and operation B. A random sample of 50 different assemblies using operation A shows that the sample average time per assembly is 8.05 minutes, with a population standard deviation of 1.36 minutes. A random sample of 38 different assemblies using operation B shows that the sample average time per assembly is 7.26 minutes, with a population standard deviation of 1.06 minutes. Required:
For α = 0.10, is there enough evidence in these samples to declare that operation A takes significantly longer to perform than operation B?

3.06

Step-by-step explanation:

The correct answer is - 3.06

Reason -

For sample A :

mean, = 8.05          

Standard deviation, = 1.36          

Size, = 50          

For sample B :

mean, = 7.26          

Standard deviation, = 1.06          

Size, = 38

Now,

-  = 8.05 - 7.26 = 0.79

Standard deviation error, SE = √(²/ + ²/)  = 0.2580

Now,

Z-statistic = ( - )/ SE

                = 0.79/0.2580

                = 3.06

⇒Z-statistic = 3.06

the ratio of white tiles to blue tiles is 48: 16. the ratio in it's simplest form is 3: 1.

step-by-step explanation:

ratio: take the first number and add a colon next to it, then add the second number after that. make sure the ratio order matches up with the written problem!

simplest form: we can simplify the ratio 48 : 16 by dividing both terms by the greatest common factor (gcf).

the gcf of 48 and 16 is 16.

divide both terms by 16:

48 ÷ 16 = 3

16 ÷ 16 = 1

reducing to simplest form:

48 : 16 = 3 : 1