I have two stat questions I am stuck on

Historically, 10% of a large shipment of machine parts, are defective.
If random samples of 400 parts are selected, what proportion of the
samples will have between 9% and 10% defective parts?

and

Historically, 10% of a large shipment of machine parts are defective.
If random samples of 400 parts are selected, what proportion of the
samples will have less than 8% defective parts?

If someone can help me please send an email

Bob

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