Answer:
Internal validity
Step-by-step explanation:
The internal validity here is weak
Internal validity describes the extent to which an evidence weighs the cause and effect claim. In this study, the internal validity that brought about failure in the new exam is mainly due to the environment where the exam was written and not the new exam itself.
So this validity is weak in claiming that the new exam is not a good substitute for the old exam.
Putting them in the same good environment might help the researchers to draw a better conclusion.
The body temperatures of a group of healthy adults have a bell-shaped distribution with a mean of 98.19degreesF and a standard deviation of 0.61degreesF. Using the empirical rule, find each approximate percentage below. a. What is the approximate percentage of healthy adults with body temperatures within 3 standard deviations of the mean, or between 96.36degreesF and 100.02degreesF? b. What is the approximate percentage of healthy adults with body temperatures between 96.97degreesF and 99.41degreesF?
Answer:
a) From the empirical rule we know that within 3 deviations from the mean we have 99.7% of the data so then that would be the answer for this case.
b) [tex] z=\frac{96.97-98.19}{0.61}=-2[/tex]
[tex] z=\frac{99.41-98.19}{0.61}=2[/tex]
And within 2 deviations from the mean we have 95% of the values.
Step-by-step explanation:
For this case we know that the distribution of the temperatures have the following parameters:
[tex] \mu = 98.19, \sigma =0.61[/tex]
Part a
From the empirical rule we know that within 3 deviations from the mean we have 99.7% of the data so then that would be the answer for this case.
Part b
We can calculate the number of deviations from the mean with the z score with this formula:
[tex]z=\frac{X -\mu}{\sigma}[/tex]
And using this formula we got:
[tex] z=\frac{96.97-98.19}{0.61}=-2[/tex]
[tex] z=\frac{99.41-98.19}{0.61}=2[/tex]
And within 2 deviations from the mean we have 95% of the values.
can someone please help meee!???
A certain city's population is 120,000 and decreases 1.4% per year for 15 years.
Is this exponential growth or decay? Growth
What is the rate of growth or decay?
What was the initial amount? 120000
What is the function?
What is the population after 10 years? Round to the nearest whole number.
Answer:
Decay Problem.Decay rate, r = 0.014Initial Amount =120,000[tex]P(t)=120000(0.986)^t[/tex]P(10)=104,220Step-by-step explanation:
The exponential function for growth/decay is given as:
[tex]P(t)=P_0(1 \pm r)^t, where:\\P_0$ is the Initial Population\\r is the growth/decay rate\\t is time[/tex]
In this problem:
The city's initial population is 120,000 and it decreases by 1.4% per year.
Since the population decreases, it is a Decay Problem.Decay rate, r=1.4% =0.014Initial Amount =120,000Therefore, the function is:
[tex]P(t)=120000(1 - 0.014)^t\\P(t)=120000(0.986)^t[/tex]
When t=10 years
[tex]P(10)=120000(0.986)^10\\=104219.8\\\approx 104220 $ (to the nearest whole number)[/tex]
A payday loan store charges $40 for a one month loan of $600. What’s the annual interest rate equivalent to?
Answer:
80%
Step-by-step explanation:
rate=100×Interest/ principal × time
Interest= 40
principal= 600
time= 1 month=1/12
100%×$40×12/$600×1=80%
A tree is 12 feet tall and casts a shadow 9 feet long. A building nearby casts a shadow that measures 24 feet. How tall is the building?
(Hint: Draw a picture and Set up a proportion)
The building height is 32 feet.
Let us consider that building height is x feet.
From attached diagram shown below,
Two triangles are formed.
Apply law of similarity of triangles.
Corresponding sides are in equal proportion.
[tex]\frac{x}{24}=\frac{12}{9} \\\\9x=12*24\\\\x=\frac{12*24}{9}=32 feet[/tex]
Learn more:
https://brainly.com/question/14285697
Line segment ON is perpendicular to line segment ML
What is the length of chord ML?
0
20 units
24 units
26 units
30 units
13
P
8
M
N
Mark this and return
Answer:
The correct answer is B (24 units)
Step-by-step explanation:
When Ryan was born, he weighed 7 pounds.At 6 months, he weighed 11.2 pounds. Amanda weighed 6 pounds when she was born, and 12.9 pounds at 6 months. Which baby had a greater percent increase in weight? Explain
Answer:
✅Amanda had a greater percent increase in weight.
Step-by-step explanation:
The percent change in Ryan’s weight was 42/7 or 60%. The percent change in Amanda’s weight was 6.9/6, or 115%. Amanda had a greater percent increase in weight.
IamSugarBee
Answer:
The percent change in Ryan’s weight was 4.2/7, or 60%. The percent change in Amanda’s weight was 6.9/6 , or 115%. Amanda had a greater percent increase in weight.
Step-by-step explanation:
its the sample answer i just did it
The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, yˆ=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.Price in Dollars 23 34 40 46 47Number of Bids 1 3 4 5 7Step 1 of 6:Find the estimated slope. Round your answer to three decimal places.Step 2 of 6:Find the estimated y-intercept. Round your answer to three decimal places.Step 3 of 6:Determine if the statement "All points predicted by the linear model fall on the same line" is true or false.Step 4 of 6:Find the estimated value of y when x=46. Round your answer to three decimal places.Step 5 of 6:Determine the value of the dependent variable y^ at x=0.Step 6 of 6:Find the value of the coefficient of determination. Round your answer to three decimal places.
Answer:
1) Estimated slope = b₁ = 0.215
2) Estimated y-intercept = b₀ = -4.185
3) Not all the points predicted fall on the same straight line, but the model gives a close to ideal estimate of the line of best fit.
4) The estimated value of y when x=46 is 5.705
5) The value of the dependent variable y^ at x=0 is -4.185
6) The coefficient of determination = 0.951
Step-by-step explanation:
To solve this, we apply regression analysis
y = b₀ + b₁x
Price in Dollars | 23 | 34 | 40 | 46 | 47
Number of Bids | 1 | 3 | 4 | 5 | 7
For this question, we want to predict the number of bids (dependent variable, y), given the list price of the item (independent variable, x)
So, running the analysis on a spreadsheet application, like excel, the table of parameters is obtained and presented in the first attached image to this solution.
Σxᵢ = sum of all the independent variables (sum of all the list prices)
Σyᵢ = sum of all the dependent variables (sum of all the number of bids in the table)
Σxᵢyᵢ = sum of the product of each dependent variable and its corresponding independent variable
Σxᵢ² = sum of the square of each independent variable (list prices)
Σyᵢ² = sum of the square of each dependent variable (number of bids)
n = number of variables = 5
The scatter plot and the line of best fit is presented in the second attached image to this solution
Then the regression analysis is then done
Slope; m = b₁ = [n×Σxᵢyᵢ - (Σxᵢ)×(Σyᵢ)] / [nΣxᵢ² - (∑xi)²]
Intercept b: b₀ = [Σyᵢ - m×(Σxᵢ)] / n
Mean of x = (Σxᵢ)/n
Mean of y = (Σyᵢ) / n
Sample correlation coefficient r: r =
[n*Σxᵢyᵢ - (Σxᵢ)(Σyᵢ)] ÷ {√([n*Σxᵢ² - (Σxᵢ)²][n*Σyᵢ² - (Σyᵢ)²])}
And -1 ≤ r ≤ +1
All of these formulas are properly presented in the third attached image to this answer
The table of results; mean of x, mean of y, intercept, slope, regression equation and sample coefficient is presented in the fourth attached image to this answer.
Hence, the regression equation is
y = -4.185 + 0.215x
y = b₀ + b₁x
Intercept = b₀ = -4.185
Slope = b₁ = 0.215
And the regression coefficient = 0.951 (Which is very close to 1 and indicates statistic significance)
Hence, we can use this answer obtained to answer the questions attached
1) Find the estimated slope.
Estimated slope = b₁ = 0.215
2) Find the estimated y-intercept.
Estimated y-intercept = b₀ = -4.185
3) Determine if the statement "All points predicted by the linear model fall on the same line" is true or false.
Taking a few of sample data
x = 23 when y = 1
y = -4.185 + 0.215x
y = -4.185 + 0.215 (23) = 0.76 ≈ 1
x = 34, y = 3
y = -4.185 + 0.215 (34) = 3.125 ≈ 3
Hence, it is evident that not all the points predicted fall on the same straight line, but the model gives a close to ideal estimate of the line of best fit.
4) Find the estimated value of y when x=46.
The linear model is
y = -4.185 + 0.215x
when x = 46
y = -4.185 + 0.215(46) = 5.705
5) Determine the value of the dependent variable y^ at x=0.
y = -4.185 + 0.215x
when x = 0
y = -4.185 + 0.215(0) = -4.185
6) Find the value of the coefficient of determination.
The coefficient of determination = regression coefficient = 0.951 (as calculated above)
Hope this Helps!!!
Math Is TU parallel to VW explain
Answer: C ( yes, both lines have a slope of 2/3. )
Step-by-step explanation:
Answer: C
Step-by-step explanation:
Which value of x is a solution to the inequality 4x-3<5x+6
Answer:x greater than -9
Step-by-step explanation:
A solid lies between planes perpendicular to the x-axis at xequals=0 and xequals=1212. The cross-sections perpendicular to the axis on the interval 0less than or equals≤xless than or equals≤1212 are squares with diagonals that run from the parabola y equals negative 2 StartRoot x EndRooty=−2x to the parabola y equals 2 StartRoot x EndRooty=2x. Find the volume of the solid.
Question:
A solid lies between planes perpendicular to the x-axis at x=0 and x=12. The cross-sections perpendicular to the axis on the interval 0≤x≤12 are squares with diagonals that run from the parabola y=-2√x to the parabola y=2√x. Find the volume of the solid.
Answer:
576
Step-by-step explanation:
Given:
Length of diagonal square:
[tex] D = 2\sqrt{x} - (-2\sqrt{x}) [/tex]
[tex] D = 4\sqrt{x} [/tex]
Here, the diagonal is the hypotenus of a right angle triangle, with leg S, where the square has a side of length S.
Using Pythagoras theorem:
[tex] S^2 + S^2 = D^2 [/tex]
[tex] S^2 + S^2 = (4\sqrt{x})^2 [/tex]
[tex] 2S^2 = 16x [/tex]
Divide both sides by 2
[tex] S^2 = 8x [/tex]
Thus,
Area, A = S² = 8x
Take differential volume, dx =
dV = Axdx
dV = 8xdx
Where limit of solid= 0≤x≤12
Volume of solid, V:
V =∫₀¹² dV
V = 8 ∫₀¹² xdx
V = [4x²]₀¹²
V = 4 (12)²
V = 12 * 144
= 576
Volume of solid = 576
PLEASE HELP Last year Lenny had an annual earned income of $58,475. He also had passive income of $1,255, and capital gains of $2,350. What was Lenny’s total gross income for the year?
a.
$58,475
b.
$59,730
c.
$60,985
d.
$62,080
Please select the best answer from the choices provided
A
B
C
D
Answer:
D
Step-by-step explanation:
8,36 : 1,6
pleaseeeeeeeeee
Answer:
209 : 40 or 5.225 : 1
Step-by-step explanation:
Your calculator can tell you the ratio 8.36/1.60 is 5.225. Writing that decimal as a fraction, you can factor out 25 to get ...
8.36 : 1.6 = 5.225 : 1 = 5225 : 1000 = (25)(209) : (25)(40) = 209 : 40
Q5. Calculate the median value of this data set. 24 -8 -17 32 -1 -28
Answer:
The median value in this set is -4.5
Step-by-step explanation:
Reorder the numbers from least to greatest
-28,-17,-8,-1,24,32
Then, since there is 6 digits in this data set there is no defined median value. In the numbers 1 to 8 there are 8 different numbers, the middle of 1 to 8 is 4.5. Then since were using the numbers -8,-1 the middle is -4.5
The tree diagram below shows all of the possible outcomes for flipping three coins.
What is the probability of one of the coins landing on tails and two of them landing on heads?
A) 1/4
B) 3/8
C) 1/2
D) 3/4
Answer:
B
Step-by-step explanation:
In that scenario, you would have one T and two H's, in any order. Looking at the chart, this happens in 3 different scenarios. Since there are a total of 8 possible outcomes, the probability of this happening is 3/8 or answer choice B. Hope this helps!
Answer:B
Step-by-step explanation: the number of event is 3 event={HHT, HTH,THH }
And the number of sample space is 8
By using 2^n formula our n is 3 2^3 = 8
The probability = 3/8
Hope it helps
Brainliest please
What are the solutions of the equation 9x^4 – 2x^2 – 7 = 0? Use u substitution to solve
Answer:
[tex]x=1\\x=-1[/tex]
Step-by-step explanation:
[tex]9x^{4} -2x^{2} -7=0\\y=x^{2} \\9y^{2} -2y-7=0\\y=\frac{2\pm\sqrt{(-2)^{2} -4*9(-7)} }{2*9} =\frac{2\pm\sqrt{4+252} }{18} =\frac{2\pm\sqrt{256} }{18}[/tex]
[tex]\sqrt{256} =16[/tex]
[tex]y=\frac{2+16}{18} =\frac{18}{18} =1 \\or \\y=\frac{2-16}{18} =-\frac{14}{18} =-\frac{7}{9}[/tex]
[tex]x^{2} = 1 \\or \\x^{2} =-\frac{7}{9}[/tex]
[tex]x=\pm 1[/tex]
[tex]x^{2} =-\frac{7}{9}[/tex] has no solution since fot all [tex]x[/tex] on the real line, [tex]x^{2} \geq 0[/tex] and [tex]-\frac{7}{9} < 0.[/tex]
The m∠ABC = (10x-5)°and m∠CBD=35°. If the angles are supplementary, find the value of x.
Answer:
15
Step-by-step explanation:
Supplementary angles completes each other to 180°
if the teo angles are supplementary here the the sum of 10x - 5 + 35 should be 180°
10x - 5 + 35 = 180
10x + 30 = 180
10x = 150
x = 15
Find the area of the smaller sector.
Round to the nearest tenth.
Help needed fast
Answer:
About 22.2 square feet
Step-by-step explanation:
First, you need to find the area of the full circle. The area of a circle is \pi r^2, which in this case is:
[tex]\pi r^2 = \pi \cdot 7.13^2\approx 159.628[/tex]
Now, since the sector is only 50 out of the total 360 degrees in a circle, you need to multiply this value by 50/360, which yields and area of about 22.2 square feet. Hope this helps!
Which of the following is an arithmetic sequence?
2.4.8. 16.
2.4.-6.8.
-8, -6,-4,-2
Answer:
-8,-6,-4,-2 is an Arithmetic sequence, because there common difference is 2.
Here's a graph of a linear function. Write the
equation that describes that function.
Express it in slope-intercept form.
Help please !!!
Answer:
y=2x-4
Step-by-step explanation:
Let x represent the number. Use the given conditions to write an equation. Solve the equation and find the number.
The product of 8 and a number is 96. Find the number.
Write an equation for the given conditions.
Answer:
12
Step-by-step explanation:
8x=96
x=96/8
x=12
Answer:
12
Step-by-step explanation:
8x=96
96/8
x=12
so the the product of 8and 12=96
are supplementary angles, then
A) Both should be acute B) Both should be obtuse C) one acute other right D) None of these
Answer:
D
Step-by-step explanation:
Answer:
D) None of these
Step-by-step explanation:
Supplementary pairs must equal to 180 degrees. They can either be made up of two right angles, or one acute and one obtuse angle.
The graph shows the amount of protein contain in a certain brand of peanut butter. Which statement describes the meaning of the point (6, 30) on the graph?
A.) There are 6 g of protein per tablespoon of peanut butter.
B.) There are 30 g of protein per tablespoon of peanut butter.
C.) There is 6 g of protein in 30 tablespoons of peanut butter.
D.) There are 30 g of protein in 6 tablespoons of peanut butter.
Answer:
D.) There are 30 g of protein in 6 tablespoons of peanut butter.
Step-by-step explanation:
Interpretation of the graph:
x-axis: tablespoons
y-axis: grams of protein.
Which statement describes the meaning of the point (6, 30) on the graph?
(6,30) means that x = 6 and y = 30.
This means that in 6 tablespoons there are 30g of protein.
So the correct answer is:
D.) There are 30 g of protein in 6 tablespoons of peanut butter.
Answer:
The answer is D
simplify (6 1/4)^4
a. 6^4
b. 1/6
c. 6^16
d. 6
Answer:
D not sure if its right tho
Answer:6
Step-by-step explanation:
Dominique is thinking about buying a hosue for 286000
Answer:
is this supposed to be a question?
Answer:
yah so
Step-by-step explanation:
Graph the equation below by plotting the
y-intercept and a second point on the
line.
Answer:
Step-by-step explanation:
On the y-axis, graph the point on (0,4). Then from there, go up one, and to the right 4.
Choose the equation of the graph shown below:
y = |x - 1| - 3
y = |x + 1| - 3
y = |x - 1| + 3
Answer:
y=[x+1]-3 because it's at the end of the line
how much alcohol must be added to 480grams of hand sanitizer that is 24% alcohol to make it a hand sanitizer that is 40% alcohol?
Answer:
what she/he said
Step-by-step explanation:
Convert 88 ounces to pounds.
A.0.18 pounds
B.5.5 pounds
C.1408 pounds
Answer: it is b because 2.5 lbs = 40 oz. then i know that 40 is half of 80 then there is not way it is the 1000 pound choice
Step-by-step explanation:
I need some help please
Answer:
ofn
Step-by-step explanation:
Answer:
Step-by-step explanation:
Since there are 44 average people out of 80. We can do this,
Total students : 600
Checked: 80
Average: 44
Number of averaged throughout the school: 600/80 * 44
l: 7.5 * 44
Thus it is: 330 average students