Two ride-sharing companies are competing for business in a large city. To help customers compare the companies, a data scientist selects a random sample of 40 completed rides from each of the two companies. From each sample, he computes the mean amount of time that passed between when the request for a pickup was placed and when the customer was picked up. Company A took, on average, 18 minutes to pick up customers with a standard deviation of 4 minutes. Company B took, on average, 12 minutes to pick up customers with a standard deviation of 10 minutes. (a) Construct and interpret a 98% confidence interval for the difference in mean response time for these two ride-sharing companies.
Solution :
Given :
[tex]$n_1 = n_2 = 40$[/tex]
[tex]$\overline X_1 = 18$[/tex]
[tex]$S_1 = 4$[/tex]
[tex]$\overline X_2 = 12$[/tex]
[tex]$S_2 =10$[/tex]
So we want to test :
[tex]$H_0 : \mu_1=\mu_2 $[/tex] vs [tex]$H_1 : \mu_1 \neq \mu_2 $[/tex]
a). For 98% confidence interval :
[tex]$=\left((\overline X_1 - \overline X_2) \pm Tn_1+n_2-2, \alpha / 2 \sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}}\right)$[/tex]
[tex]$=\left((18-12) \pm 2.375 \sqrt{\frac{4^2}{40}+\frac{10^2}{40}}\right)$[/tex]
[tex]$=(6 \pm 4.0445)$[/tex]
= (1.956, 10.045)
Factor x2+4x+3.
O A. (x-3)(x+1)
O B. (x-3)(x-1)
O C. (x+3)(x+1)
O D. (x+3)(x-1)
QUICKKKKKKKK!!!!
Answer:
c. (x +3)(x + 1)
Step-by-step explanation:
Factoring an equation is a way of expressing an equation as the product of other linear expressions. The following expression,
[tex]x^2 +4x +3[/tex]
Can be represented as the product of the following,
[tex](x+3)(x+1)[/tex]
To check this, one can distribute, one of the expressions over the other, then simplify, the result should be the starting expression,
[tex](x+3)(x+1)\\[/tex]
Distribute,
[tex](x)(x)+(1)(x)+(3)(x)+(3)(1)[/tex]
Simplify,
[tex]x^2 +x +3x + 3\\[/tex]
[tex]x^2 +4x +3[/tex]
A consumer group surveyed the prices for white cotton extra-long twin sheet sets in five different department stores and reported the average price as $16 with standard deviation $3.81. Assume that the population is normal and has a standard deviation equal to $3.81. 9. Provide a 95% confidence interval in order to estimate the average price of the white cotton extra-long twin sheets. z* is 1.96
Answer:
95% confidence interval in order to estimate the average price of the white cotton extra-long twin sheets.
(12.6604 ,19.3396)
Step-by-step explanation:
Step(i):-
Given that mean of the sample = 16
Given that the standard deviation of the sample = 3.81
The standard deviation of the Population = 3.81
Level of significance = 0.05
Step(ii):-
95% confidence interval in order to estimate the average price of the white cotton extra-long twin sheets.
[tex](x^{-} - Z_{0.05} \frac{S.D}{\sqrt{n} } , x^{-} + Z_{0.05} \frac{S.D}{\sqrt{n} } )[/tex]
([tex](16 - 1.96 (\frac{3.81)}{\sqrt{5} } , 16 +1.96 (\frac{3.81)}{\sqrt{5} })[/tex]
( 16 - 3.3396 , 16 + 3.3396)
(12.6604 ,19.3396)
Final answer:-
95% confidence interval in order to estimate the average price of the white cotton extra-long twin sheets.
(12.6604 ,19.3396)
Find the next term in the sequence 3, 6, 9, 15, 24,
Factor 16a + 10.
(Please help)
Answer:
2(8a+5)
Step-by-step explanation:
To factor means to find a number that can divide all the terms in the expression and leave whole number quotients. The factor is written outside the bracket while the quotients are written inside the bracket. In the question, 2 can divide both 16a and 10 giving 8a and 5. This is how the answer was obtained.
Please help really quick
Answer:
88 yd.²
Hope this helps!
Answer:
Area= 88 sq. yd.
Step-by-step explanation:
The formula for the area of a triangle is A= h b/2.
This means you just divide 16 (the base) by 2 to get 8, and then multiply it by 11 (the height). This gives you 88
The trajectory of a golf ball in a chip from the rough has a parabolic pattern. The height, in feet, of the ball is given by the equation h(x)=−.15x2+3.2x, where x is the number of feet away from the golf club (along the ground) the ball is.
The ball reaches a maximum height of _______ feet at a horizontal distance of ____
feet away from the golf club it was hit with.
The ball returns to the ground at about ________ feet away.
9514 1404 393
Answer:
maximum height of 17.07 feet about 10.67 feet from the club
returns to the ground 21.33 feet away
Step-by-step explanation:
A graphing calculator can answer these questions easily.
The vertex of the quadratic ax²+bx+c is given by x=-b/(2a). For this quadratic function, the highest point is found at ...
x = -(3.2)/(2(-0.15)) = 32/3 = 10 2/3 . . . . feet horizontally from the club
The maximum height is the function value at that point.
h(10 2/3) = (-0.15(10 2/3) +3.2)(10 2/3) = 1.6(10 2/3) = 17 1/15
The ball reaches a maximum height of 17 1/15 feet at a horizontal distance of 10 2/3 feet from the club. The ball's flight is symmetrical about the peak, so it returns to the ground about 21 1/3 feet away.
Answer now please ♀️
Answer:
8/15
Step-by-step explanation:
In a right triangle, where B is an acute angle, the tan B is equal to the measure of the side opposite B divided by the measure of the shorter side at B
tanB = 16/30 = 8/15
This figure was broken into a triangle and a parallelogram as shown. Use the figures to complete the statements. The height of the triangle his in. The area of the triangle is vin.? The area of the parallelogram is in. 2 ? The area of the irregular figure is in. 2. ? h 22 in. 8 in. 10 in. Nin. 8 in. 8 in.
Answer: Use the figures to complete the statements.
The height of the triangle h is
✔ 12
in.
The area of the triangle is
✔ 48
in.2.
The area of the parallelogram is
✔ 80
in.2.
The area of the irregular figure is
✔ 128
in.2.
Step-by-step explanation: I js now got it right by the power of guessing
What is the value of 6(x + 15) - 12 when x = 12?
provided on your answer document.
Answer: 162
Step-by-step explanation:
6(12+15) Following the order of operations, (P.E.M.D.A.S), you should do parentheses first. So you add 12 and 15 to get 27. Were left with 6(27). So we multiply 6 and 27. The final answer is 162.
4
27
x 6
--------
162
Mr. Ledford is concerned about the amount of sleep the students in his district are getting. He selects a random sample of 14 seniors in his district and asks them how many hours of sleep they get on a typical school night. He then uses school records to determine the most recent grade-point average (GPA) for each student. His regression output along with a residual plot and a histogram of the residuals are given below.
Sleep (hrs) 9 8.5 9 7 7.56 7 5.5 6 8.5 6.5 8
GPA 3.8 3.3 3.5 3.6 3.4 3.3 3.2 3.2 3.2 3.4 3.6 3.1 3.4 3.7
Required:
Do these data provide convincing evidence of a linear relationship between the hours of sleep students typically get and their academic performance, as measured by their GPA?
Answer:
Hence, the data provides convincing evidence that a linear relationship exists between hours of sleep observed and academic performance as measured by GPA.
Step-by-step explanation:
Given the data:
Sleep (hrs) 9 8.5 9 7 7.56 7 5.5 6 8.5 6.5 8
GPA 3.8 3.3 3.5 3.6 3.4 3.3 3.2 3.2 3.2 3.4 3.6 3.1 3.4 3.7
The scatter plot shows a positive linear trend. With the correlation Coefficient depicting a R value of 0.56. The residual plot also depicts a a randomly scattered values of the residual values. Similarly, a plot of the normal values of residuals
The data provided has a linear correlation between the hours of sleep observed and academic performance as measured by GPA.
What is correlation?It is defined as the relation between two variables which is a quantitative type and gives an idea about the direction of these two variables.
We have given data of the 14 seniors shown in the table.
To solve this question we will calculate the correlation coefficient 'r'
The formula for correlation coefficient :
[tex]\rm r =\frac{n\sum xy-\sum x \sum y}{\sqrt{[n\sum x^2-(\sum x)^2]}[n\sum y^2-(\sum y)^2]} }[/tex]
From the table the value of n = 14
[tex]\rm \sum x = 104.5[/tex] , [tex]\rm \sum y =47.7[/tex] , [tex]\rm \sum xy =357.8[/tex] , [tex]\rm \sum x^2 =797.25[/tex] , [tex]\rm \sum y^2 =163.09[/tex]
Put all the values in the above formula we get:
[tex]\rm r =\frac{14\times357.8-104.5 \times47.7}{\sqrt{[14\times 797.25-104.5^2][14\times163.09-47.7^2]} }[/tex]
[tex]\rm r = \frac{5009.2-4984.65}{\sqrt{(241.25)(7.97)} }[/tex]
[tex]\rm r = \frac{24.55}{43.849}[/tex]
r = 0.559 ≈ 0.56
The value of the correlation coefficient is 0.56 which is between the values 0.5 to 0.7 shows that the variables are moderately correlated.
Thus, the data provided has a linear correlation between the hours of sleep observed and academic performance as measured by GPA.
Learn more about the correlation here:
brainly.com/question/11705632
Find the area of the garden.
Answer:
28yd²
Step-by-step explanation:
area of square = side *side
=6*6= 36²
area of rectangle (patio)= length* breadth
=4*2=8²
area of garden= area of square - area of rectangle
=36-8
=28 yd²
Answer:
28 sq. ydStep-by-step explanation:
For finding the area of the garden :First Case:
Given,
Side of the big square = 6 yd
Therefore,
Area of the big square = side × side
= 6yd × 6yd
[tex] = 36 {yd}^{2} [/tex]
Second Case:
Length of the patio = 4 yd
Breadth of the patio = 2 yd
Therefore,
Area of the patio = Length × Breadth
= 4yd × 2yd
[tex] = 8 {yd}^{2} [/tex]
Last Case:
According to first and second cases,
Area of the garden
= Area of the big square - Area of the patio
[tex] = 36 {yd}^{2} - 8 {yd}^{2} [/tex]
[tex] = 28 {yd}^{2} [/tex]
Hence,Required area of the garden is 28 sq. yd (Ans)
Add 8/9+4/9 and Simplify the answer and write as a mixed number.
Answer:
1 1/3
Step-by-step explanation:
Answer:
12/9= 1 and 1/3
Step-by-step explanation:
need help ASAP plssssssssssssssssss
3,945 ÷ 45 = (?)
R (?)
Helpppppppppppppppppppppppppppppppppp
Easyyy
Answer:
duuuuuuude if its easy then why do you need help huh answer me
Step-by-step explanation:
Select all numbers that have an absolute value of 4.
You didnt give us the numbers but it should be 4 and -4
Aling Nora bought 15 kilos of beef worth 1,845. How much is a kilo oof beef?
Answer:
1845/15=123
Step-by-step explanation:
Step-by-step explanation:
I don't now just paiattention to the problem that willed be more like it thx
Draw a square that has (-2,4) and (3,-1) as two of its vertices
Answer:
square with (-2,4) and (3,-1) vertices
number 10 step by step :(
The circumference of a circle is like the ________ of a figure.
A. shape
B. perimeter
C. area
Answer:
The answer would be 'B. perimeter'.
The radius of a circle is 18 inches. What is the circle's area?
Answer:
1017.88 inches
Step-by-step explanation:
Area = πr2 = π x 182 ≈ 1017.87602
Jimmy has 317 of feet of chord for his science experiment. James has 3/5
feet of chord for his science experiment as well. (a) How many feet of
chord do they have altogether? (b) Who has more chord, Jimmy or
James? Help please
Answer:
(a)317 and 3/5 (b) jimmy
Step-by-step explanation:
(a) 317 and 3/5 because i plus there chord both (b) no explanation cause jimmy has mire chord than james
Answer:
A.317 3/5
B.jimmy
Step-by-step explanation:
sana Po makatulong
Online entertainment streaming services have gained in popularity in recent years as an alternative to traditional television. One such company has seen steady growth in each period of 3 months, called a quarter, over the past 4 years. The scatterplot shows the relationship between the number of quarters passed since January 2014 and the number of members to the streaming service. A least-squares equation that summarizes this relationship is members hat = 1.829 (quarters) minus 18.108, with a value for r of 0.991.
A graph titled subscribers versus quarters since January 2011 has quarters since January 2011 on the x-axis, and subscribers on the y-axis. Points are in a line with positive slope.
A graph titled Residuals versus quarters since January 2011 has quarters since January 2011 on the x-axis, and Residual on the y-axis. The points curve down, and then curve up.
Based on the residual plot, is a linear model appropriate for summarizing this relationship?
A linear model is appropriate because the value of r is close to 1.
A linear model is appropriate because the residual plot is curved.
A linear model is not appropriate because the residual plot shows a clear pattern.
A linear model is not appropriate because the scatterplot relating time and subscribers shows a clear pattern.
Answer:
c hope it nhelps
Step-by-step explanation:it takes away time
Answer:
the person above me is correct!
Step-by-step explanation:
40% of 500 multiplying with decimal
Answer:
200
Step-by-step explanation:
First we need to find the decimal version of 40%
to do this we can move the decimal point 2 spaces to the left.
40% ---> 0.40
then we can multiply by 500
This is equal to 200
Answer: 200
Step-by-step explanation: 40%=.40
500•.4=200
Bruce collects coins. He collected a total of 125 coins. If 68% of the coins he collected were foreign,
how many other coins did he collect?
Bruce collected coins that were not foreign.
(Type a whole number.)
Answer:
40
Step-by-step explanation:
100 - 68 = 32
32/100 = ?/125
125 x 32 = 4,000
4,000 ÷ 100 = 40
Which are undefined terms that can be used to define other terms?
O point, segment, ray
O point, line, plane
O line, plane, cube
O line, ray, angle
Answer:
Point, Line, Plane
Step-by-step explanation: They are undefined terms because its is easier to define them using examples rather than word for word
Sid has £5 to buy apples and bananas.
He uses his money like this:
He buys 18 apples.
Then he buys as many bananas as possible.
With his change, he buys more apples.
How many apples and bananas does he buy?
(Apples=6p Each)
(Bananas= 40p Each)
(pls add working out)
Answer:
Apples: 23 , bananas = 9
Step-by-step explanation:
Apples = 18 x 6 = 108p = 1,08£
5-1,08 = 3,92£
£3,92 = 392p
Bananas = 392 : 40 = 9,8= 9
40x9 = 360p = 3,60£
change = 3,92 -3,60 = 32p
apples = 32 : 6 = 5,33 = 5
total apples = 23
Andrew wrote the number 186,425 on the board. In which number is the value of the digit 4
exactly 100 times the value of the digit in the number Andrew wrote?
A 681,452
B 462,017
C 246,412
D 124,655
Answer:
C
Step-by-step explanation:
The four is in the hundreds so times one hundred it'd be in the 10,000 so it is C.
Kei buys a table and 12 chairs. Each chair cost the same price. The table cost $165. The total cost for the table and 12 chairs is $ 465. What is the cost of one chair?
Answer:
[tex]165 + 12c = 465[/tex]
Is the right answer
Answer:$25 per chair
Step-by-step explanation:
It’s $165 for only the table. Minus that from the $465 and you get $300. Do $300 divided by 12(amount of chairs) And you get $25. It’s $25 per 1 chair.
The mean midday temperature recorded in June in a city in South California is 36ºC, and the standard deviation is 3ºC. The number of days in the month of June is 30.
Assuming the data is normally distributed, the number of days in June when the midday temperature was between 39ºC and 42ºC is .
Answer:
About 4 days
Step-by-step explanation:
Convert 39 and 42 degrees C to a z score and then use the z-table
The number of days in June when the midday temperature was between 39°C and 42°C is equal to 4.0 days.
Given the following data:
Mean midday temperature = 36°C.
Standard deviation = 3°C.
How to determine the number of days in June?In order to determine the number of days in June when the midday temperature was between 39°C and 42°C, we would determine the z-score as follows:
Let the midday temperature be M.
P(39 < M < 42) = 1 - [P(M < 39) + P(M < 42)]
Evaluating, we have:
P(M < 39) = P(Z < [39 -36/3])
P(M < 39) = P(Z < [3/3])
P(M < 39) = P(Z < 1).
P(M < 39) = 0.84134.
P(M < 42) = P(Z < [42 -36/3])
P(M < 42) = P(Z < [6/3])
P(M < 42) = P(Z < 2)
P(M < 42) = 0.02275.
Substituting the parameters into the formula, we have;
P(39 < M < 42) = 1 - [P(M < 39) + P(M < 42)]
P(39 < M < 42) = 1 - [0.84134 + 0.02275]
P(39 < M < 42) = 1 - 0.86409
P(39 < M < 42) = 0.13591.
Now, we can determine the number of days in June when the midday temperature was between 39°C and 42°C:
No. of days = 0.13591 × 30
No. of days = 4.0 days.
Note: There are 30 days in the month of June.
Read more on z-scores here: https://brainly.com/question/4302527
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