Michelle is three times as old as Fiona. Fiona is twice as old as Madeline. Madeline is seven years old. How old is Michelle?

a drivet who drives at a speed of r mph for t hr will travel a distance d mi giveb by d = rt mi. how far will a driver travel at

Pavel [41]

D = RT ,
D = 59 × 5
D = 295 m

8 0

3 years ago

Alexander is a stockbroker he earns 11% commission each week last week he sold $7,200 worth of stocks how much money did he make

AlekseyPX

Answer:

Last week Alexander earned $792 in commissions.

Step-by-step explanation:

Giving the following information:

Commission= 11%

Sales= $7,200

T<u>o calculate the total commission, we need to use the following formula:</u>

Total commission= commission rate*sales

Total commission= 0.11*7,200

Total commission= $792

Last week Alexander earned $792 in commissions.

3 0

3 years ago

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:

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