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3 years ago

Yasmin took a survey of her classmates to determine the frequencies of different eye colors

Mathematics

1 answer:

dexar [7]3 years ago

7 0

The answer is 29 classmates.

-Blue has 7 people
-Brown has 15 people
-Green has 4 people
-Hazel has 3 people

When all added up 29 classmates.

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A polygon has an angle sum of 360°, and each angle measures 90°. What is the polygon?

Mkey [24]

The polygon is definitely a rectangle, and it could be a square.

7 0

3 years ago

HELP WITH MATHH!!!!!!!!!!

riadik2000 [5.3K]

Answer:

Area of parallelogram : bh.

3×5=15

Step-by-step explanation:

not that hard and no matter how you turn a shape, the dotted line is always the height/altitude.

7 0

3 years ago

Among persons donating blood to a clinic, 85% have Rh+ blood (that is, the Rhesus factor is present in their blood.) Six people

Leona [35]

Answer:

a) There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) There is a 22.36% probability that at most four of the six have Rh+ blood.

c) There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

Step-by-step explanation:

For each person donating blood, there are only two possible outcomes. Either they have Rh+ blood, or they do not. This means that we use the binomial probability distribution to solve this problem.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinatios of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.85, n = 6$ .

a) fine the probability that at least one of the five does not have the Rh factor.

Either all six have the factor, or at least one of them do not. The sum of the probabilities of these events is decimal 1. So:

$P(X < 6) + P(X = 6) = 1$

$P(X < 6) = 1 - P(X = 6)$

In which:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

$P(X < 6) = 1 - P(X = 6) = 1 - 0.3771 = 0.6229$

There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) find the probability that at most four of the six have Rh+ blood.

Either more than four have Rh+ blood, or at most four have. So

$P(X \leq 4) + P(X > 4) = 1$

$P(X \leq 4) = 1 - P(X > 4)$

In which

$P(X > 4) = P(X = 5) + P(X = 6)$

$P(X = 5) = C_{6,5}.(0.85)^{5}.(0.15)^{1} = 0.3993$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

$P(X > 4) = P(X = 5) + P(X = 6) = 0.3993 + 0.3771 = 0.7764$

$P(X \leq 4) = 1 - P(X > 4) = 1 - 0.7764 = 0.2236$

There is a 22.36% probability that at most four of the six have Rh+ blood.

c) The clinic needs six Rh+ donors on a certain day. How many people must donate blood to have the probability of obtaining blood from at least six Rh+ donors over 0.95?

With 6 donors:

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

37.71% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 7 donors:

$P(X = 6) = C_{7,6}.(0.85)^{6}.(0.15)^{1} = 0.3960$

0.3771 + 0.3960 = 0.7764 = 77.64% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 8 donors

$P(X = 6) = C_{8,6}.(0.85)^{6}.(0.15)^{2} = 0.2376$

0.3771 + 0.3960 + 0.2376 = 1.01 = 101% probability of obtaining blood from at least six Rh+ donors over 0.95.

There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

5 0

3 years ago

Esteban finds 12 baseball cards on Monday and 24 more baseball cards on Tuesday. He gives some baseball cards to his sister, and

mojhsa [17]

Answer:

23 cards.

Step-by-step explanation:

After Monday, Esteban has 12 cards.

After Tuesday, Esteban has 12 + 24 = 36 cards.

He gave to his sister x cards.

36 - x = 13

36 = 13 + x

23 = x

5 0

3 years ago

Verify that triangle ABC is equal to DEF . Find the scale factor of triangle ABC to triangle DEF

alexira [117]

Answer:

k = 6 : 5 : 4

Step-by-step explanation:

BC : AB : AC = 18 : 15 : 12 = 6 : 5 : 4

EF : DE : DF = 12 : 10 : 8 = 6 : 5 : 4

5 0

2 years ago