I NEED HELP WITH NUMBER 4 and I need to show work :((

x = 1, y = 9

Step-by-step explanation:

y = 7 + 2x

4x + 3(7 + 2x) = 31

4x + 21 + 6x = 31

10x = 10

x = 1

y = 7 + 2(1)

y = 9

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;

180-142=38 for the acute angle next to the entry

90+38=128

180-128=52

a=52

step-by-step explanation: