1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
just olya [345]
3 years ago
9

All the fourth-graders in a certain elementary school took a standardized test. A total of 81% of the students were found to be

proficient in reading, 74% were found to be proficient in mathematics, and 64% were found to be proficient in both reading and mathematics. A student is chosen at random.(a) What is the probability that student is proficient in mathematics but not in reading?(b) What is the probability that student is proficient in reading but not in mathematics?
Mathematics
1 answer:
Dvinal [7]3 years ago
5 0

Answer:

The probability that a student is proficient in mathematics, but not in reading is, 0.10.

The probability that a student is proficient in reading, but not in mathematics is, 0.17

Step-by-step explanation:

Let's define the events:

L: The student is proficient in reading

M: The student is proficient in math

The probabilities are given by:

P (L) = 0.81\\P (M) = 0.74\\P (L\bigcap M) = 0.64

P (M\bigcap L^c) = P (M) - P (M\bigcap L) = 0.74 - 0.64 = 0.1\\P (M^c\bigcap L) = P (L) - P (M\bigcap L) = 0.81 - 0.64 = 0.17

The probability that a student is proficient in mathematics, but not in reading is, 0.10.

The probability that a student is proficient in reading, but not in mathematics is, 0.17

You might be interested in
The sum of a + b is an odd number if
Grace [21]

Answer:

a is an even number and b is an odd number

Step-by-step explanation:

if a is even and b is even then the sum would be even ex.10+6=16. I'd a and b are both odd the sum would be even ex. 13+9=22. one has to be odd and one has to be even for the sum to be odd ex. 5+4=9

8 0
3 years ago
The fair spinner shown in the diagram above is spun.
Katena32 [7]

Unable to provide a definitive answer due to lack of diagram.

Answer: 1/4

Step-by-step explanation:

Multiples of 6:

Multiples of 6 are numbers obtained when 6 is multiplied by an integer. Such as

(6*1) = 6, (6*2)=12, (6*3) = 18..... and so on.

Probability is calculated by finding the ratio of the required outcome and total possible outcomes.

Probability = required outcome / Total possible outcomes

P(multiple of 6) = number of multiples of 6 / total number of possible outcomes

If number of 6 multiples = 5 and

Total number of faces in the spinner = 20

Then :

P(multiple of 6) = 5/20 = 1/4

5 0
3 years ago
A doctor wants to estimate the mean HDL cholesterol of all​ 20- to​ 29-year-old females. The number of subjects needed to estima
Ludmilka [50]

Answer:

n=(\frac{1.64(14.7)}{3})^2 =64.57 \approx 65

So the answer for this case would be n=65 rounded up to the nearest integer

And the sample size would decrease by 160-65=95 subjects

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

\bar X represent the sample mean for the sample  

\mu population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size  

ME represent the margin of error

The confidence interval for the mean is given by the following formula:

\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}   (1)

2) Solution to the problem

Since the new Confidence is 0.90 or 90%, the value of \alpha=0.1 and \alpha/2 =0.05, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that z_{\alpha/2}=1.64

Assuming that the deviation is known we can express the margin of error is given by this formula:

ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}    (a)

And on this case we have that ME =\pm 3 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

n=(\frac{z_{\alpha/2} \sigma}{ME})^2   (b)

Replacing into formula (b) we got:

n=(\frac{1.64(14.7)}{3})^2 =64.57 \approx 65

So the answer for this case would be n=65 rounded up to the nearest integer

And the sample size would decrease by 160-65=95 subjects

8 0
3 years ago
Which of the following operations is true regarding relative frequency distributions? Multiple choice question. No two classes c
pshichka [43]

Answer:

The relative frequency is found by dividing the class frequencies by the total number of observations

Step-by-step explanation:

Relative frequency measures how often a value appears relative to the sum of the total values.

An example of how relative frequency is calculated

Here are the scores and frequency of students in a maths test

Scores (classes)              Frequency                Relative frequency

0 - 20                                10                               10 / 50 = 0.2

21 - 40                               15                               15 / 50 = 0.3

41 - 60                               10                               10 / 50 = 0.2

61 - 80                                5                                 5 / 50  = 0.1

81 - 100                             <u> 10</u>                                10 / 50 = <u>0.2</u>

                                          50                                               1

From the above example, it can be seen that :

  1. two or more classes  can have the same relative frequency
  2. The relative frequency is found by dividing the class frequencies by the total number of observations.
  3. The sum of the relative frequencies must be equal to one
  4. The sum of the frequencies and not the relative frequencies is equal to the number of observations.

4 0
3 years ago
URGENT PLEASE HELP !!!!!
Mumz [18]

Answer:

Let P represent the number of pies sold and J represent the number of juices sold.

a)

The first equation for the sum of the sales:

P + J = 79

P = 79 - J

Next, for the sum of the amounts earned:

1.65P + 1.36J = 118.17

Substituting P,

1.65 (79 - J) + 1.36J = 118.17

J = 42

Using this value of J,

P = 79 - 42

P = 37

b)

Mr. Sanchez's class earned: 1.65 x 37 = $61.05

Mr. Kelly's class earned: 1.36 x 42 = $57.12

So Mr. Sanchez's class earned more money.

c) Mr. Sanchez's class earned:

61.05 - 57.12

= $3.93 more than Mr. Kelly's class

Step-by-step explanation:

:)

4 0
3 years ago
Other questions:
  • Rewrite each expression below using the distributive property then evaluate each expression for X equals two and Y equals five.
    7·1 answer
  • What is the measure of angle 1
    5·2 answers
  • a jar has 170 coins. there are 50 more pennies than nickels. twice as many quarters as nickels. what are the coins?
    10·1 answer
  • How can you solve an equation with the variable on both sides?
    11·1 answer
  • Which is a correct description of the polygon?
    7·2 answers
  • A group of 6 students was asked, "How many hours did you watch television last week? Here are their responses.
    15·1 answer
  • Which of the following are the most likely factors of the function graphed above?
    15·1 answer
  • What is x in 1/150/1/200x2=x
    11·1 answer
  • Nick has a 6-digit code he remembers it as three 2-digit numbers The first number is between 10 and 20. The second number is 3 t
    15·1 answer
  • Water leaks through a roof and collects in a bucket the table shows how many cups of water collect in the bucket for different n
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!