Answer:
The minimum sample size needed is 39.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.99}{2} = 0.005[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.005 = 0.995[/tex], so Z = 2.575.
Now, find the margin of error M as such
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Assuming that the standard deviation of the number of hours is 120 hour
This means that [tex]\sigma = 120[/tex]
The minimum sample size needed in order to construct a 99% confidence interval for the mean number of hours of flight time of all such pilots, to within 50 hours, is about?
The minimum sample size needed is n.
n is found when [tex]M = 50[/tex]
So
[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]
[tex]50 = 2.575\frac{120}{\sqrt{n}}[/tex]
[tex]50\sqrt{n} = 2.575*120[/tex]
[tex]\sqrt{n} = \frac{2.575*120}{50}[/tex]
[tex](\sqrt{n})^2 = (\frac{2.575*120}{50})^2[/tex]
[tex]n = 38.19[/tex]
Rounding up
The minimum sample size needed is 39.
PLEASE ANSWER ASAP DUE IN 2 MIN WILL GIVE BRAINLEST!!!!!!!!!!!!!!!!
PLEASE ONLY ANSWER PART B
Answer:
because cfd eaquls a+b lllllllllll
Answer:
Step-by-step explanation:
IT is either the same as 7x+4 because it is infront of each other or you add 8x+6 and 6x+2 then you substract that from 180 to find out the remaining angle. Of course you have to subtitute the amount of x first.
Adult tickets to a basketball game cost $5. Student tickets cost $1. A total of $3,142 was collected on the sale of 1,330 tickets. How many of each type of ticket were sold?
The basketball game sold
______adult tickets and
_______student tickets.
Answer:
453 adult tickets and 877 student tickets were sold.
Step-by-step explanation:
Given that adult tickets to a basketball game cost $ 5 and student tickets cost $ 1, and a total of $ 3,142 was collected on the sale of 1,330 tickets, to determine how many of each type of ticket were sold the following calculations must be performed:
5 - 1 = 4
1330 x 1 = 1330
3142 - 1330 = 1812
1812/4 = 453
1330 - 453 = 877
877 x 1 + 453 x 5 = X
877 + 2265 = X
3142 = X
Therefore, 453 adult tickets and 877 student tickets were sold.
Write the exponential equation
A. y = 2.5(2)^x
B. y = 10(1/2)^x
C. y = 2(2.5) ^x
D. y = 1/2(10)^x
Answer:
A. y = 2.5(2)^x
Step-by-step explanation:
Given that when
x = 1, f(x) = 5
x = 2, f(x) = 10
x = 3, f(x) = 20
x = 4, f(x) = 40
x = 5, f(x) = 80
x = 6, f(x) = 160
Considering all the options
y = 2.5(2)^x
Substitute x = 1
y = 2.5(2)^1 = 2.5 *2 = 5
Substitute x = 2
y = 2.5(2)^2 = 2.5 * 4 = 10
Substitute x = 3
y = 2.5(2)^3 = 2.5 * 8 = 20
Substitute x = 6
y = 2.5 (2)^6
= 2.5 * 64
= 160
Since the function is true for all the values of x substituted, then the answer is A. y = 2.5(2)^x
Melissa bought 2 shirts and 3 skirts and spent between $45 and $60. Each shirt costs the same amount. Each skirt costs the same amount. The price of a shirt is $12. What is the least amount Melissa could have spent on a skirt? What is the most Melissa could have spent of a skirt?
Answer:
Least is 7
Most is 12
Step-by-step explanation:
So 2 shirts for 12.
So 24
Take 24 off of both
Left with 21 to 36
21÷3 is 7
36÷3 is 12
Hope this helps
Answer:
least - $7
most - $12
Explanation:
if the price of a shirt is $12, she must have spent at least $24 on the shirts in total.
the least amount melissa could have spent on a skirt is:
($45 - $24) ÷ 3 = $7
and the most she could have spent is:
($60 - $24) ÷ 3 = $12
i hope this helps! :D
Stella was out at a restaurant for dinner when the bill came. Her dinner came to $10. She wanted to leave a 25% tip. How much was her meal plus the tip, before tax, in dollars and cents?
Answer:
12.50
Step-by-step explanation:
What is 37/40 in simplest form
Answer:
It is already explained in simplest form
Step-by-step explanation:
It can be written as 0.925 in decimal form (rounded to 6 decimal places).
Can someone please help me out pleaseeeee !!!!!
Answer:
Step-by-step explanation:
0: -2
1: -4
2: -6
Which of the fractions is equivalent to 2/5?
Answer:
4/10, 6/15, 8/20, 10/25
Step-by-step explanation:
An artist uses 18 colors on an art palette to paint a picture. This is 72% of all the colors on the palette. How many colors are on the artist’s palette?
Answer:
25
Step-by-step explanation:
Find the area of the following composite figure
Answer:
1713
Step-by-step explanation:
952+288+472=1713
During the month of April, Samantha Kept
track of the number of days she saw a
hummingbird in her garden. She saw a
hummingbird 18 days during that 30 day
month. Based on this information, how
many days will she see a hummingbird
during the 180 day summer?
Answer:
she will see 108 humming birds
Step-by-step explanation:
30x6= 180
so mutiply how many times she sees one in a month by 6
Answer:
3240
Step-by-step explanation:
Find the area of the polygon.
c. Translate the follom
4.) 51 - (x+5)
5.) 3(7-8)
Step-by-step explanation:
1. 51-x-5
= 46-x Answer
2. 21-24
= -3 Answer
Please help me please hurry
Answer
899
Step-by-step explanation:
99
4(x + 1) + 8 = 24
how do i solve this
Answer: x = 3
First, you can multiply the 4 with the x and the 1:
4x + 4 + 8 = 24
Now, you just add the 4 and the 8 together:
4x + 12 = 24
Subtract 12 from both sides:
4x = 12
Now you divide by 4 from both sides
x = 3
^ and that's your final answer!
Answer:
x=3
Step-by-step explanation:
4x+4+8=24
4x+12=24
4x=12
4x/4=12/4
(x=3)
A chili cook-off has adult tickets (a) and child tickets (c) . A group of Visitors buy three adult tickets and two child tickets and pays a total of $26. Another group buys five adult tickets and 3 child tickets and pays $42. Write and solve a system of equations to find the price of each type of ticket. (I just need the equations)
Answer:
Equation 1 would be: 3a+2C
Equation 2 would be: 5a+3C
Step-by-step explanation:
Emily grows flowers on part of her 2-acre farm. Her house
and barn cover half an acre, her vegetable gardens cover
1 1/4 acres, and her flower garden covers the rest of her
farm. She divides the flower garden into 16 equal-sized
plots and puts 4 kinds of flowers in each plot.
How large is each plot of flowers in Emily's garden?
Answer:
1/64 for each type f flowe
Step-by-step explanation:
3. P343. 13. A sociologist is interested in surveying workers in computer-related jobs to estimate the proportion of such workers who has changed jobs within the past years. (a) In the absence of preliminary data, how large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05? (b) In a sample of 100 workers, 20 of them had changed jobs within the past year. Find a 95% confidence interval for the proportion of workers who have changed jobs within the past year. (c) Based on the data in part (b), estimate the sample size needed so that the 95% confidence interval will specify the proportion to within ±0.05.
Answer:
a) A sample of 385 must be taken.
b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
c) A sample of 246 is needed.
Step-by-step explanation:
Question a:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
Absence of preliminary data:
This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?
A sample of n must be taken.
n is found when [tex]M = 0.05[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96*0.5[/tex]
Dividing both sides by 0.05
[tex]\sqrt{n} = 1.96*10[/tex]
[tex](\sqrt{n})^2 = (19.6)^2[/tex]
[tex]n = 384.16[/tex]
Rounding up,
A sample of 385 must be taken.
Question b:
In a sample of 100 workers, 20 of them had changed jobs within the past year.
This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]
The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).
Question c:
Same procedure as question a, just with [tex]\pi = 0.2[/tex]
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]
[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]
[tex]n = 245.8[/tex]
Rounding up
A sample of 246 is needed.
Nathaniel is using the quadratic formula to solve 0 = x2 + 5x - 6. His steps are shown below/attached
What are solutions to the equations
Answer:
A
Step-by-step explanation:
Answer:
x= -6 ,1
Step-by-step explanation:
B is the answer
x= -6 ,1
71 is 10% of what number?
52 is 97% of what Number?
Explain steps.
Answer:
71 is 10% of 710
52 is 97% of 5200/97
Step-by-step explanation:
Let’s start with 71 is 10% of what number.
basically, what this is saying, is that 71 = 10% times and unknown valu. We can set this as x.
so, 71=0.1x
divide on both sides,
710=x
now the second one.
repeat the same process.
52=0.97x
divide
5200/97 =x
Please I need help. The Median of a data set is 100. Which statement about the data set must be true?
A. The data set has an average of 100
B. Half the data values are greater than 100.
C. The minimum value is 80 and the maximum value is 120
D. Only one of the data points in the data set has a value of 100
Answer:The mean, or average, has the property that distances from the mean to the individual ... The measure of center where half the values of the data set lie above this ... The maximum value of a data set is 200 and the minimum value is 80. ... 25 b. 24 c. 100 d. 5 e. 120. e. 120. A factorial is the product of all number from 1 to n.
Step-by-step explanation:
Answer:
B. Half the data values are greater than 100.
Step-by-step explanation:
The median is just another way to say the number in the middle. So if in the whole group of numbers 100 is in the middle, that means that half of the numbers will be bigger than 100, and half of the numbers will be smaller than 100.
C2>a2+b2 is it a obtuse right or acute
Answer:
obtuse
Step-by-step explanation:
When c, the hypotenuse, is greater than the legs (a and b), it's an obtuse triangle
Verify the Identity.
tan²xsin²x = tan²x-sin²x
tan²(x) - sin²(x) = sin²(x)/cos²(x) - sin²(x)
… = sin²(x) (1/cos²(x) - 1)
… = sin²(x) (sec²(x) - 1)
… = sin²(x) tan²(x)
The four members of the Taylor family each buy an airplane ticket each member I had to pay an extra $30 fee for checking in luggage if the total cost of the trip is 540.50 what is the price of each plane ticket
Answer:
$105.13
Step-by-step explanation:
[540.50 - (4 x 30)]/4 = $105.125
Name the marked angle in 2 different ways.
V
U
S
T
Answer:
VUS, UST
Step-by-step explanation:
3. The third side of a triangle measures (3x-5) cm. If the length of the midline is 14 m,
what is x?
A 8
C. 10
B. 9
D. 11
Answer:
D. 11
Step-by-step explanation:
Midsegment theorem:
The length of the midsegment of a triangle is half the length of it's third side.
In this question:
Third side: 3x - 5
Midsegment: 14m
So
[tex]\frac{3x - 5}{2} = 14[/tex]
[tex]3x - 5 = 28[/tex]
[tex]3x = 33[/tex]
[tex]x = \frac{33}{3}[/tex]
[tex]x = 11[/tex]
The correct answer is given by option D.
What is the volume of the square pyramid?
John invests $15,000 in a savings account that pays 2.5% simple interest. If John makes no
withdrawals or deposits into the account, how much will be in the account after 9 years?
Answer:
18,375
Step-by-step explanation:
Ellie is an African elephant. When she was born, she weighed about 200 pounds. As an adult, she weighs 7 tons! How many pounds did Ellie gain over her lifetime?
Answer:
13,800 pounds
Step-by-step explanation:
one ton = 2000 pounds
7 tons = 14,000 pounds
14,000 - 200 = 13,800 pounds
"An education researcher recorded the number of books students read over the last year and the number of vocabulary words that students defined correctly on a test of 100 vocabulary words. The resulting data were used to conduct a hypothesis test to investigate whether there is a positive linear relationship between the number of books read and the number of vocabulary words defined correctly. What are the correct hypotheses for the test?"
Answer:
B
Step-by-step explanation: