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
Anastasy [175]
2 years ago
5

Jacob scored 85%, 90%, and 74% on his first three tests. Then he scored 99%, 84% and 75% on his next three

Mathematics
1 answer:
AlekseyPX2 years ago
3 0
The average of the first three is 83 (85 + 90 + 74)/3
The average of the next 3 is 86.

The difference is 3
You might be interested in
Question 24 Multiple Choice Worth 1 points)
hammer [34]

Given:

The system of equations is:

Line A: y=x-4

Line B: y=3x+4

To find:

The solution of given system of equations.

Solution:

We have,

y=x-4              ...(i)

y=3x+4           ...(ii)

Equating (i) and (ii), we get

x-4=3x+4

-4-4=3x-x

-8=2x

Divide both sides by 2.

-4=x

Substituting x=-4 in (i), we get

y=-4-4

y=-8

The solution of system of equations is (-4,-8).

Now verify the solution by substituting x=-4, y=-8 in the given equations.

-8=-4-4

-8=-8

This statement is true.

Similarly,

-8=3(-4)+4

-8=-12+4

-8=-8

This statement is also true.

Therefore, (-4,-8) is a solution of the given system of equations, because the point satisfies both equations. Hence, the correct option is C.

8 0
2 years ago
Assume the average height for American women is 64 inches with a standard deviation of 2 inches. A sorority on campus wonders if
satela [25.4K]

Answer:

a) s = 0.4

b) Z = 2.5

c) 99th percentile.

d) The larger sample size would lead to a smaller margin of error, which would lead to a higher z-score and a increased percentile.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the z-score of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean \mu and standard deviation \sigma, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean \mu and standard deviation s = \frac{\sigma}{\sqrt{n}}.

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Assume the average height for American women is 64 inches with a standard deviation of 2 inches

This means that \mu = 64, \sigma = 2

A) Calculate the standard error for the distribution of means.

Sample of 25 means that n = 25, so s = \frac{2}{\sqrt{25}} = 0.4.

B) Calculate the z statistic for the sorority group.

Sample mean of 65 means that X = 65.

Z = \frac{X - \mu}{\sigma}

By the Central Limit Theorem

Z = \frac{X - \mu}{0.4}

Z = \frac{65 - 64}{0.4}

Z = 2.5

C) What is the approximate percentile for this sample? Enter as a whole number.

Z = 2.5 has a p-value of 0.9938, so 0.99*100 = 99th percentile.

D) If the sorority actually had 36 members (still with an average of 65 inches), would you expect the percentile value to increase or decrease? why?

The larger sample size would lead to a smaller margin of error, which would lead to a higher z-score and a increased percentile.

3 0
2 years ago
A ball is dropped from a cliff that is 135 m high.
Anna [14]

Answer:

113 feet

Step-by-step explanation:

I will assume you meant h = -4.9t^2 + 135; "t2" is incorrect.

To answer this question, to find the height of the ball after 2.1 seconds, substitute 2.1 for t in the above equation:

h(2.1) = -4.9(2.1)^2 + 135.  This becomes -21.6 + 135, or 113.4.

The closest result to the height of the ball after 2.1 seconds is 113 feet.

4 0
2 years ago
A study of 250 households in Cedar Bluff showed that a household produced an average of 4 pounds of garbage per day. What is the
Juli2301 [7.4K]

Answer:

Step-by-step explanation:

Given that a study of 250 households in Cedar Bluff showed that a household produced an average of 4 pounds of garbage per day.

Here a study of only 250 were made to assess about the entire households in Cedar Bluff

Hence the population of interest in this study is the entire households in Cedar Bluff.

The sample is the 250 households in Cedar Bluff which were studied

The objective was to study the sample and from that information to assess about the population.

6 0
3 years ago
Is 1.1 less than or greater than or equal to the square root of two
dangina [55]

Answer:

less than

Step-by-step explanation:

the Square root of 2 is 1.4142...

3 0
3 years ago
Other questions:
  • The standard deviation of a population is known to be 7.8. If The sample size is 85, what is the standard error of the mean?
    6·1 answer
  • I need help with fractions :(
    13·2 answers
  • H(x)=16-x, when x= -4​
    14·1 answer
  • What is that answers ? please
    13·1 answer
  • Marlon is mixing blue paint and yellow paint in the ratio of 2:3 to make green paint. If he uses 8 liters of blue paint, how man
    11·1 answer
  • Which statement or statements are true about adding integers?
    12·1 answer
  • Can U solve this?!<br><br> No Improper answers!
    6·2 answers
  • Saitima could take Goku <br><br> True or false? <br><br> Be sure to explain your reasoning
    5·1 answer
  • Hello can anyone help me with this question please and thank you
    8·1 answer
  • Type​ A, type​ B, and type C lightbulbs are lasting longer today than ever before. On​ average, the number of bulb hours for a t
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!