2x+5=12
2x=7
x=3.5
3.5*6=21
21+20=41
Hope this helps :)
Step-by-step explanation:
that means that in 5 ml there are 250mg.
and that means that in 1 ml there are 250/5 = 50 mg.
and now we can find out the mg in 7 ml (by multiplying everything by 7) :
7 ml = 50 × 7 = 350 mg
35 students - 25 % ( or 1/4 of the all students )
35 * 4 = 140
140 - 35 = 105
Answer:
The number of students who liked skating was 105.
Answer:
90% confidence interval for the population mean is between a lower limit of $92.18 and an upper limit of $107.82.
Step-by-step explanation:
Confidence interval for a population mean is given as mean +/- margin of error (E)
mean = $100
sd = $25.20
n = 30
degree of freedom = n-1 = 30-1 = 29
confidence level (C) = 90% = 0.9
significance level = 1 - C = 1 - 0.9 = 0.1 = 10%
critical value (t) corresponding to 29 degrees of freedom and 10% significance level is 1.699
E = t×sd/√n = 1.699×25.20/√30 = $7.82
Lower limit of population mean = mean - E = 100 - 7.82 = $92.18
Upper limit of population mean = mean + E = 100 + 7.82 = $107.82
90% confidence interval is ($92.18, $107.82)
Answer:
it is -5
Step-by-step explanation:
