Mrs. Lofton's Test Grades
Test 1
Test #2
Count
Mrs. Lofton created a histogram of her first two test grades for her class. If she combines the two tests, what proportion of the
grades were a 70 or higher?

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step-by-step explanation:

hi there!

the answer will be d: 2

my answer got deleted but it's a

step-by-step explanation:

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;