1. The probability that your mail is delivered before 2 pm is 0.9, so the probability that the mail is delivered at 2 pm or after 2 pm (so not before 2 pm) is 1-0.9=0.1.
Remark: 0.9=9/10=90/100=90%, and 0.1 is 10%
2. Probability of the mail being delivered before 2 pm for 2 consecutive days is
3. take a look at the picture attached, the tree diagram is another method we could use.
Answer:
c. 6
Step-by-step explanation:
Given
See attachment for graph
Required
Average rate of change
This is calculated as:
Where
So, we have:
Using the attached graph, we have:
So, we have:
Answer:
cos B = 
tan B = 
sin B = 
Step-by-step explanation:
In the right triangle, there are three sides and 2 acute angles
- Hypotenuse ⇒ the opposite side of the right angle
- Leg1 and Leg 2 ⇒ the sides of the right angle
The trigonometry functions of one of the acute angles Ф are
- sin Ф = opposite leg/hypotenuse
- cos Ф = adjacent leg/hypotenuse
- tan Ф = opposite leg/adjacent leg
In Δ ACB
∵ ∠C is the right angle
∴ AB is the hypotenuse
∵ AC is the opposite side of ∠B ⇒ leg1
∵ CB is the adjacent side of ∠B ⇒ leg2
→ By using the ratios above
∴ cos B = 
, tan B = 
, sin B = 
∵ CB = 7, AB = 25, AC = 24
∴ cos B =
∴ tan B =
∴ sin B =
Answer:
ok
Step-by-step explanation:
Answer:
And the explanation of this number is:"The number of text messages for Kendra it's 2.26 deviations above the mean"
Step-by-step explanation:
1) 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".
2) Calculate the z score
Let X the random variable that represent the number of text messages per month, and for this case we know the distribution for X is given by:
Where 
and 
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And the explanation of this number is:"The number of text messages for Kendra it's 2.26 deviations above the mean"
