Answer:
x=2
Step-by-step explanation:
10x2=20
20+1=21
Answer:
?
Step-by-step explanation:
Answer:
65% profit
-25% discount
Step-by-step explanation:
cost price = 40+25 = 65% higher than marked price
discount = -25%
Answer:
c. (12.12, 18.48)
Step-by-step explanation:
Hello!
The study variable is X: number of times a racehorse is raced during its career.
The average number is X[bar]= 15.3 and the standard deviation is S= 6.8 obtained from a sample of n=20 horses.
To estimate the population mean you need that the variable has a normal distribution, in this case, we have no information about its distribution so I'll assume that it has a normal distribution. With n=20 the most accurate statistic to use for the estimation is a Students-t for one sample, the formula for the interval is:
X[bar] ± 

[15.3 ± 2.093 *
]
[12.12; 18.48]
Using a significance level of 95% you'd expect that the true average of times racehorses are raced during their career is included in the interval [12.12; 18.48].
I hope it helps!
I'm not in High School (Me is in Middle School) so... But, I got B.