Most dermatologists recommend using sunscreens that have a Sun Protection Factor (SPF) of at least 30. One of the authors wanted
1 answer:
Answer:
95% confidence interval = ( 28.9485, 40.1515 )
Step-by-step explanation:
sample size( n ) = 52
mean value ( x )= 34.55
std ( б ) = 20.12
H0 : <em>u </em>≤ 30
Ha : u > 30 ( claim )
95% confidence interval for mean SPF level ( df = 51 )
= mean value ±
95% confidence interval = ( 28.9485, 40.1515 )
we cannot reject H0
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Answer:
0.11
Step-by-step explanation:
Probability that house sale will increase = P(A) = 0.25
Probability that interest rate on house loans will go up = P(B) = 0.74
Probability that either house sales will go up or interest rates will go up = P(A or B ) = 0.89
We have to find the probability that neither house sales nor interest rates will increase. This event is the compliment of the event that either house sales will go up or interest rates will go up.
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