Which of the following are expressions? Check all that are true.

A. y = 5/b

B. 275

C. 52 = 25

D. x

E. 3(5x + 7)

correct answer:

b.(19,-2)

y=3n + 1

step-by-step explanation:

this is wrong because it says the second number is one less and i added one instead

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;