18 is 20% of what number

20%   of a number means  

20/100    of a number.  

20/100=0.2 we can say that  

 0.2

x

, where  

x

is a number we don't know,  

=

18

.

0.2

x

=

18

Divide both sides by  

0.2

.

x

=

90

We can check this by finding  

20 %

of  

90

and seeing that it is equal to  

18

.

90(0.2)=18

Step-by-step explanation:

hi there!

the answer will be d: 2

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;