Question
In: Math
In a random sample of 24 fifth graders who took an IQ test, the average score...
In a random sample of 24 fifth graders who took an IQ test, the average score was 101.48 with a standard deviation of 13.34. Assuming that the IQ scores are normally distributed, what will be the 98% confidence interval for the average IQ scores for all fifth graders?
Select the best answer.
96.3054 to 106.6546
95.5521 to 107.4079
96.8131 to 106.1469
94.6728 to 108.2872
Solutions
Expert Solution
Solution :
Given that,
= 101.48
s =13.34
n = 24
Degrees of freedom = df = n - 1 = 24- 1 = 23
At 98% confidence level the t is ,
= 1 - 98% = 1 - 0.98 = 0.02
/
2 = 0.02 / 2 = 0.01
t
/2,df = t0.01,23 = 2.4999
Margin of error = E = t/2,df
* (s /
= 2.4999 * ( 13.34/
=6.8072
The 98% confidence interval for the average IQ scores for all fifth graders
- E < 
<
+ E
101.48 - 6.8072 <
< + 101.48+6.8072
94.6728 <
< 108.2872
94.6728 to 108.2872
CORRECT OPTION IS LAST
94.6728 to 108.2872
milcah answered 1 month agoRelated Solutions
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