1. Mang Pedro uses the kaing to assess his harvest of mangoes. After he has

used a certain kind of fertilizer, the mangoes yield the following per kaing.


100 92 110 112 90 98 97 106 100 100

90 98 120 108 96 92 95 98 92 102

88 102 98 88 89 90 102 100 100 97

102 100 100 86 87 100 105 97 93 96

89 98 96 96 92 100 98 98 92 100


Consider each kaing (a group) a random sample. From past harvests, the

population standard deviation was observed to be 8 mangoes. Find the point and

the interval estimates of the population mean per kaing, using 98% confidence.


Step 1: The parameter of interest is the mean of the population where the

sample comes from.


Step 2: The sample information consists of raw scores = _____, and = _____.

The sample size of 50 kaing is large enough for the Central Limit Theorem

to satisfy the assumption that the sampling distribution of means is

normally distributed. The -test is also applicable.


Step 3: The level of confidence is _____ or = _____.

Critical values: _____.

This means that if more random samples are taken from the target

population and an interval estimate is made for each sample, then 95%

of the intervals ill contain the true parameter value.

Step 4: ̅ =

__+__+__+⋯+__

__

= ___ ≈ ___ mangoes

(the sample mean)

The point estimate is 98.


Step 5: = /2 (



√

)

= ___ (

___

√___

)

= _____

Interval estimate

̅ − /2 (



√

) < < ̅ + /2 (



√

)

̅ − _____ (

___

√___

) < < ̅ + _____ (

___

√___

)

_____ − _____ to _____ + _____

_____ to _____ or _____ to _____


Step 6: Result

We can say that __________________________________

_______________________________________________.​