1/2 percent, round to three positions

The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airp

motikmotik

Answer:

The 95% confidence interval for the population mean rating is (5.73, 6.95).

Step-by-step explanation:

We start by calculating the mean and standard deviation of the sample:

$M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M=\dfrac{1}{50}(6+4+6+. . .+6)\\\\\\M=\dfrac{317}{50}\\\\\\M=6.34\\\\\\s=\sqrt{\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M)^2}\\\\\\s=\sqrt{\dfrac{1}{49}((6-6.34)^2+(4-6.34)^2+(6-6.34)^2+. . . +(6-6.34)^2)}\\\\\\s=\sqrt{\dfrac{229.22}{49}}\\\\\\s=\sqrt{4.68}=2.16\\\\\\$

We have to calculate a 95% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

The sample mean is M=6.34.

The sample size is N=50.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

$s_M=\dfrac{s}{\sqrt{N}}=\dfrac{2.16}{\sqrt{50}}=\dfrac{2.16}{7.071}=0.305$

The degrees of freedom for this sample size are:

$df=n-1=50-1=49$

The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_M=2.01 \cdot 0.305=0.61$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 6.34-0.61=5.73\\\\UL=M+t \cdot s_M = 6.34+0.61=6.95$

The 95% confidence interval for the mean is (5.73, 6.95).

4 0

3 years ago

An electronics store receives a shipment of 35 graphing calculators including 7 that are defective. eight calculators are chosen

spin [16.1K]

There are 23535820 combinations that can be made of 35 calculators taken 8 at a time.

$_{35}C_8=\frac{35!}{8!27!}=23535820$

8 0

2 years ago

What valie of x makes the equation true

Arada [10]

Answer:

x = 1.25

Step-by-step explanation:

-3x+10 = 5x-8

+3x +3x

10 = 8x - 8

+8 +8

18 = 8x

x = 18/8

x = 1 1/4 = 1.25

3 0

2 years ago

Please help i’ll give brainliest

Natalija [7]

Problem 1 Answer: x = 2/3y+8

Show Work:

Step 1: Add 2y to both sides.

3x−2y+2y=24+2y

3x=2y+24

Step 2: Divide both sides by 3.

3x/3 = 2y+24/3

x = 2/3y+8

Problem 2 Answer: x=−2y+48

Show Work:

Add -2y to both sides.

x+2y+−2y=48+−2y

x=−2y+48

8 0

3 years ago

Whats answere y+2=-3 (x - 4)

faust18 [17]

Answer:

Slope = 6.000/2.000 = 3.000

x-intercept = 10/3 = 3.33333

y-intercept = -10/1 = -10.00000

Step-by-step explanation:

Slope is defined as the change in y divided by the change in x. We note that for x=0, the value of y is -10.000 and for x=2.000, the value of y is -4.000. So, for a change of 2.000 in x (The change in x is sometimes referred to as "RUN") we get a change of -4.000 - (-10.000) = 6.000 in y. (The change in y is sometimes referred to as "RISE" and the Slope is m = RISE / RUN)

4 0

2 years ago

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