In a study of 225 adults, the mean heart rate was 72 beats per minute. Assume the population of heart rates is known to be approximately normal with a standard deviation of 10 beats per minute. What is the 90% confidence interval for the mean beats per minute?

Question

anonymous · Answer

70.7 – 73.3 

 70.9 – 73.1 

 70.7 – 73.1 

 70.9 – 73.3

anonymous · Answer

@ganeshie8 ?

amistre64 · Answer

what will be the middle of the interval?

anonymous · Answer

72?

amistre64 · Answer

yes,  now a zscore relates to us how far from the mean a certain value of x is:  and each zscore has relates to a specific percentage.

what z score is related to an area of 45% from the mean?  if you have left tails then adding 50% gives us  a zscore of 95% from teh left side

amistre64 · Answer

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