Question

Grades on a standardized test are known to have a mean of

10901090

for students in the United States. The test is administered to

458458

randomly selected students in Florida; in this sample, the mean is

1104.171104.17

and the standard deviation

(s)

is

117.72117.72.

The 95% confidence interval for the average test score for Florida students is

(nothing,

nothing).

(Round

your responses to two decimal

places.)

Answer #1

t critical value at 0.05 level with 457 df = 1.965

95% confidence interval for is

- t * S / sqrt(n) < < + t * S / sqrt(n)

1104.17 - 1.965 * 117.72 / sqrt( 458) < < 1104.17 + 1.965 * 117.72 / sqrt( 458)

1093.36 < < 1114.98

95% CI is **( 1093.36 , 1114.98)**

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