Sarah got a 80% on her pre algebra final exam. if there were 75 questions total how many did sarah get correc? How many did she get wrong? what percent did she get wrong? HELP PLS

Sarah got 60 questions correct, 15 questions wrong, and she got 20% of the questions wrong.

Step-by-step explanation:

First, let's solve for how many questions Sarah got correct.

80% as a fraction can be simplified as . To find how many questions Sarah answered correctly, we can set up a proprtional relationship as follows:

Next, after we cross multiply, 8 X 75 = 600, and 600 ÷ 10 = 60

So, Sarah got 60 out of 75 questions correct.

To find how many she missed, we can simply subtract 60 from 75 to get 15.

So, Sarah got 15 out of 75 questions wrong.

Finally, to find the percentage of the questions that Sarah got wrong, we can use the 15 out of 75 incorrect questions that we found earlier to create a percentage.

15 ÷ 75 = 0.2

0.2 X 100 = 20

So, Sarah got 20% of the questions wrong.

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.

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;