Please help i am having difficulty

A survey of 1000 air travelers1 found that 60 % prefer a window seat. The sample size is large enough to use the normal distribu

stira [4]

Answer:

The 90% confidence interval is 0.575 to 0.625.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence interval $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

Z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 1000, \pi = 0.60$

90% confidence interval

So $\alpha = 0.1$ , z is the value of Z that has a pvalue of $1 - \frac{0.1}{2} = 0.95$ , so $z = 1.645$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.60 - 1.645\sqrt{\frac{0.60*0.40}{1000}} = 0.575$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.60 + 1.645\sqrt{\frac{0.60*0.40}{1000}} {119}} = 0.625$

The 90% confidence interval is 0.575 to 0.625.

3 0

3 years ago

If you have $200 and you spend it all ( how much will you have (earned) in 1 year?

QveST [7]

Answer: if you save $200 per month (with 2% interest compounded monthly) If you save $200 per month are are getting 2% interest on your money, you will have saved $2,400 and earned $26.16. The total result at the end of the year will be $2,426.16.

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

For every £1.00 a company spends on advertising, it spends £0.75 on its website. Express the amount spent on advertising to the

Mandarinka [93]

Answer:

4:3

Step-by-step explanation:

For every £1.00 a company spends on advertising, it spends £0.75 on its website.

From the above question:

The ratio is given as:

Amount spent on advertising : Amount spent on website

= £1.00 : £0.75

Convert ratio sign to division

= 1/0.75

Multiply Numerator and Denominator by 100

= 1 × 100 / 0.75 × 100

= 100/75

= 4/3

= 4 : 3

Therefore, the ratio in its simplest form = 4:3

4 0

3 years ago

A vertical lamppost of height 6 m is at P When Sam stands at the point A. the shadow formed is 2.1 m long. When Sam stands at th

Damm [24]

Step-by-step explanation:

triangle ADA' and OPA' are similar so, using property of similar triangles :

6/AD = (13.3+3.6-PB'+2.1)/2.1

{A'P = 13.3 +3.6 - PB' + 2.1}

6/AD = (16.9-PB'+2.1)/2.1

6/AD = (19-PB')/2.1 - EQN I

As we know, AD = BC as both of them are Sam's height (constant)

triangle OPB' and BCB' are similar so, using property of similar triangles:

6/BC = PB'/3.6

OR, 6/AD = PB'/3.6 (AD = BC) - EQN II

Now,

comparing EQN I AND II we get :

(19-PB')/2.1 = PB'/3.6

or, 68.4 - 3.6PB' = 2.1PB'

or, 68.4 = 5.7PB'

so, PB' = 12 m

Now, as we know,

6/BC = PB'/3.6

OR, 6/BC = 12/3.6

OR, (6×3.6)/12 = BC

So, the height of Sam is 1.8 m.

tanA' = AD/AA'

<A' = tan‐¹(1.8/2.1)

<B' = tan‐¹(1.8/3.6)

Now,

<A'OB' = 180 - tan‐¹(1.8/2.1) - tan‐¹(1.8/3.6)

<A'OB' = 112.833

7 0

2 years ago

Kevin cuts lawns during the summer months. He charges $10 plus $5 per hour. The algebraic model is C = 5h + 10, where C represen

Dafna1 [17]

Answer:

We have;

Hours (h), Total cost C

1, 5*1 + 10 = $15

2, 5*2 + 10 = $20

3, 5*3 + 10 = $25

4, 5*4 + 10 = $30

5, 5*5 + 10 = $35

Step-by-step explanation:

The given parameters are;

Kevin's fixed charge for lawn cutting = $10

Kevin's charge for lawn cutting per hour = $5

The total cost, C, for cutting lawn cutting by Kevin is C = 5h + 10

7 0

4 years ago