Answer:


And the mean would be:

And the standard deviation of total time would be:


Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let total life time of t four transistors T = X1 + X2 + X3 + X4 (where X1,X2,X3 and X4 are life time of individual transistors
For this case the mean length of time that four transistors will last


And the mean would be:

And the standard deviation of total time would be:


Answer: 45
Step-by-step explanation:
300 * 0.15 = 45
Answer:
27.4 feet down deep
Step-by-step explanation:
28 feet down, swins up for 0.3 feet times 6 or 1.8 feet up
leaving a total of 26.2 under the sea and he swims back down at 0.3 feet times 4 or 1.2 feet down. and the new total is 26.2 + 1.2 which equals 27.4 feet down in the deep sea
The answer is
26 degrees
I just did the test hope this helps :)
Answer:

Step-by-step explanation:

Expanding brackets.

Adding 2m and 6 to both sides.

Combining like terms.

Dividing both sides by 14.
