A sample of 169 observations showed an average of 15 and a standard deviation of 26. Construct the 88% confidence interval for the population mean. What is the upper limit of this interval

18.11

Step-by-step explanation:

The formula for Confidence Interval is given as:

Confidence Interval = μ ± z × σ /√n

μ = the population mean/average = 15

σ = the population standard deviation = 26

z = z score of 88% confidence interval = 1.5548

= 15 ± 1.5548× 26/√169

= 15 ± 1.5548 × 26/13

= 15 ± 1.5548 × 2

= 15 ± 3.11

Hence,

Confidence Interval = 15 ± 3.11

Lower Limit

= 15 - 3.11

= 11.89

Upper limit

= 15 + 3.11

= 18.11

Therefore, the upper limit of the 88% confidence interval is 18.11

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1

the 2 figures are congruent bc if you reflect abcd over the y axis then over the d axis the figures overlap