What is the approximate percent decrease from 1,865 to 1,240? 33.5% 50% 66.5% 150%

Candice is preparing for her final exam in Statistics. She knows she needs an 65 out of 100 to earn an A overall in the course.

sertanlavr [38]

Answer:

a. 72

b. 816

c. 570

d. 30

Step-by-step explanation:

Given the graph is a bell - shaped curve. So, we understand that this is a normal distribution and that the bell - shaped curve is a symmetric curve.

Please refer the figure for a better understanding.

a. In a normal distribution, Mean = Median = Mode

Therefore, Median = Mean = 72

b. We have to know that 68% of the values are within the first standard deviation of the mean.

i.e., 68% values are between Mean Standard Deviation (SD).

Scores between 63 and 81 :

Note that 72 - 9 = 63 and

72 + 9 = 81

This implies scores between 63 and 81 constitute 68% of the values, 34% each, since the curve is symmetric.

Now, Scores between 63 and 81 =

= 68 X 12 = 816.

That means 816 students have scored between 63 and 81.

c. We have to know that 95% of the values lie between second Standard Deviation of the mean.

i.e., 95% values are between Mean 2(SD).

Note that 90 = 72 + 2(9) = 72 + 18

Also, 54 = 63 - 18.

Scores between 54 and 90 totally constitute 95% of the values. So, Scores between 72 and 90 should amount to of the values.

Therefore, Scores between 72 and 90 =

= 570.

That is a total of 570 students scored between 72 and 90.

d. We have to know that 5 % of the values lie on the thirst standard Deviation of the mean.

In this case, 5 % of the values lie between below 54 and above 90.

Since, we are asked to find scores below 54. It should be 2.5% of the values.

So, Scores below 54 =

= 2.5 X 12 = 30.

That is, 30 students have scored below 54.

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

What is 80 in its simplest form as a fraction?

Ann [662]

I believe the correct given problem is:

“What is 80% in its simplest form as a fraction?”

Take note that you missed to place the percent sign which is very important.

Now to solve this, 80% when converted to decimal form is 0.80 which means that you have 80 parts per 100 parts. Therefore the fraction form of this would be 80 / 100.

fraction = 80 / 100

However this fraction is not yet the answer because we can still simplify this further. First step in simplifying is to divide both the numerator and denominator by 10 so that we are left with:

8 / 10

Next step is to divide by 2:

4 / 5

Now we can see that we can no longer divide this (numbers should be whole number). Therefore the simplest form as a fraction is 4/5

Answer:

4/5

6 0

3 years ago

If you draw four cards at random from a standard deck of 52 cards, what is the probability that all 4 cards have distinct charac

mezya [45]

There are $\binom{52}4$ ways of drawing a 4-card hand, where

$\dbinom nk = \dfrac{n!}{k!(n-k)!}$

is the so-called binomial coefficient.

There are 13 different card values, of which we want the hand to represent 4 values, so there are $\binom{13}4$ ways of meeting this requirement.

For each card value, there are 4 choices of suit, of which we only pick 1, so there are $\binom41$ ways of picking a card of any given value. We draw 4 cards from the deck, so there are $\binom41^4$ possible hands in which each card has a different value.