Answer:
Lixin obtains 15 marks
Step-by-step explanation:
Lets write two equations based on the question where: <u>D= Devi and L=Lixin</u>
D=L+15 <em>- "devi scores 15 marks more than lixin"</em>
D=2L <em>- "devi obtains twice as many marks as lexin"</em>
Now, substitute 2L as D in the first equation we wrote: (D=L+15)
2L=L+15
Next, subtract L from both sides:
<u>L=15</u>
Answer:
It has millions of tickets. On each ticket is written a number a dollar amount. The exact average and SD are unknown but are estimated from the sample to be $20,000 and $5,000 respectively.
Step-by-step explanation:
Given that:
sample size n = 1600
sample mean
= 20000
standard deviation = 5000
The objective is to choose from the given option about what most closely resembles the relevant box model.
The correct answer is:
It has millions of tickets. On each ticket is written a number a dollar amount. The exact average and SD are unknown but are estimated from the sample to be $20,000 and $5,000 respectively.
However, if draws are made without replacement, the best estimate of the average amount for the bride will be $20,000
Similarly, the standard error for the sample mean = 


the standard error for the sample mean = 125
A computer discounted at 30% off is less expensive.
First: 1000*.8 = 800
800*.9 = $720
Second: 1000*.7 = $700