the awser is (-2)(8 + 6) + (-3)
Four? Isn't it stated in the question? Unless I am assuming wrong.
Answer:
um i dont know
Step-by-step explanation:
We have been given that the distribution of the number of daily requests is bell-shaped and has a mean of 38 and a standard deviation of 6. We are asked to find the approximate percentage of lightbulb replacement requests numbering between 38 and 56.
First of all, we will find z-score corresponding to 38 and 56.


Now we will find z-score corresponding to 56.

We know that according to Empirical rule approximately 68% data lies with-in standard deviation of mean, approximately 95% data lies within 2 standard deviation of mean and approximately 99.7% data lies within 3 standard deviation of mean that is
.
We can see that data point 38 is at mean as it's z-score is 0 and z-score of 56 is 3. This means that 56 is 3 standard deviation above mean.
We know that mean is at center of normal distribution curve. So to find percentage of data points 3 SD above mean, we will divide 99.7% by 2.

Therefore, approximately
of lightbulb replacement requests numbering between 38 and 56.
The correct order is:
the probability of heads on 2nd and 4th toss only;
the probability of at least 3 tails in a row;
the probability of 3 or more heads;
the probability of consecutive tails; and
the probability of at least 2 tails.
There are 16 outcomes in the sample space.
There are 8 ways of having consecutive tails; this gives the probability 8/16.
There is 1 way of having heads on the 2nd and 4th toss only, making the probability 1/16.
There are 3 ways to have at least 3 tails in a row, making the probability 3/16.
There are 11 ways to have at least 2 tails, making the probability 11/16.
There are 5 ways to have at least 3 heads, making the probability 5/16.