Aresearcher (jack) comes to you and is interested in the average length of time a computer fan will run before it needs to be cleaned?

jack believes that this time period is approximately normally distributed with a standard deviation of 30 hours.

you tell him to take a sample of computer fans.

jack comes back to you and says that he took a random sample of 36 computers, and found that the average length of time was 876 hours.

use a 94% confidence interval.

1. 8

2. 9

3. 20

4. 3

5. 17

6. 2.2

7. 11.25

8. 1

9. 14

10. 2

step-by-step explanation:

thats the first half

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.

what

tip $2.90

total $17.40